G Environmental chemistry Unit guide - Physicslocker · G Environmental chemistry Unit guide Where this unit fits in Prior learning ... Risk assessments are required for any hazardous

G Unit guideEnvironmental chemistry

Where this unit fits in Prior learningThis unit builds on:unit 7E Acids and alkalis, unit 7F Simple chemical reactions, unit 8G Rocks and weathering and unit 8H The rock cycle, and on work on the reactions of acids in unit 9E Reactions of metals andmetal compounds.There are opportunities for citizenship education in this unit in the activities concerning theenvironment and sustainable development.This unit provides opportunities to revisit and revise topics met in other units in Years 7 and 8. Withsome pupils, teachers may wish to concentrate on some of the new topics, extending activities, and with others to spend more time on revision of previous work.

Sheet 1 of 1© Harcourt Education Ltd 2004 Catalyst 3This worksheet may have been altered from the original on the CD-ROM.

The concepts in this unit are: the land, sea and air around us make up our environment; human activities can lead to pollution ofour environment; science can be used to overcome these problems.

This unit leads onto:work in key stage 4 on changes to the atmosphere and Earth.

This unit relates to:growing plants in unit 9D Plants for food, and work on using energy resources in unit 9I Energy andelectricity. It also relates to unit 14 Can the Earth cope? Ecosystems, population and resources, andunit 23 Local action, global effects, in the geography scheme of work.

To make good progress, pupils starting thisunit need to:• know that there are differences between

soils which relate to the rocks they wereformed from

• have experience of finding the pH of avariety of solutions and be able to relatethe pH scale to the acidity of a solution.

in terms of materials and their properties NC Programme of Study Sc2 3a, c; Sc3 1g, 2e, i, 3a, e, f, g

• describe in terms of chemical reactions howacid rain arises and how it affects rocks,building materials and living things

• describe how air and water pollution aremonitored and how they might be controlled

• distinguish between different environmentalproblems.

• describe some of the consequences of acidrain and of other forms of pollution

• identify why it is important to monitor andcontrol pollution.

• describe a variety of environmental issues andexplain the implications of these.

Suggested lesson allocation (see individual lesson planning guides)Direct route

G1Environmentalchemistry

G2Acid rain

G3More about acidrain

G4Global warming

G5Looking at the evidence –Think about the strengthof the evidence

Booster 4Focus on particles 2 –Chemical changes

Extra lessons (not in Pupil book)

G2 Investigate:What makesrainwater acidic?

Review and assessprogress(distributedappropriately)

MisconceptionsMany people think that science and technology are responsible for pollution. In fact, people cause pollution; badly used science can make thisworse, well-used science can help to minimise it.

Health and safety (see activity notes to inform risk assessment)Risk assessments are required for any hazardous activity. In this unit pupils investigate soils, use a solution of sulphur dioxide and also use dilutesolutions of acids.

Expectations from the QCA Scheme of Work At the end of this unit …

… most pupils will … … some pupils will not have made so muchprogress and will …

… some pupils will have progressed furtherand will …

in terms of scientific enquiry NC Programme of Study Sc1 2b, g, i, j, k, m, n, o

• make effective use of secondary sources ofinformation about the relationship of soil typeto plant growth and record their findings usingICT

• identify and describe possible sources ofinformation about the environment and selectfrom these evidence about environmentalchange over time, identifying some strengthsand weaknesses in the evidence.

• select information from secondary sourcesrelating plants to soil type and record findingsusing ICT

• describe how some sources provide evidenceabout environmental change.

• identify and explain the strengths andweaknesses of the evidence aboutenvironmental change obtained fromsecondary sources.

G-I-Unit Guides.qxd 16-Jun-04 3:12 PM Page 1

G1Lesson

planning guideEnvironmental chemistry


Learning objectivesi Know the environment consists of the air, water and soil and how it may be polluted.ii Understand how soil forms.

Scientific enquiryiii Use indicator solution to identify soil type.

Suggested alternative starter activities (5–10 minutes)

Introduce the unit

Unit map for Environmentalchemistry.

Share learning objectives

• Describe how soil can bepolluted.

• Explain how soil forms.• Use secondary sources of

information. (Sc1)

Problem solving

Show slides or a video clipabout sedimentation.Catalyst InteractivePresentations 3

Brainstorming

In groups, pupilsbrainstorm ‘Where mightsoil pollution comefrom?’

Capture interest

Show slides or a video clipof different habitats, withdifferent ranges of plantsgrowing in each one.Catalyst InteractivePresentations 3

Suggested alternative plenary activities (5–10 minutes)

Review learning

Pupils work in groups tomatch words to definitions.

Sharing responses

Each group prepares a shortpresentation of their resultsfrom Activity G1a.

Group feedback

In groups, pupils useinformation from ActivityG1b to answer the question‘How does different soilaffect the plants that growin it?’

Brainstorming

In groups, pupils brainstormthe question ‘How can soilpH be changed?’

Looking ahead

In groups, pupils suggestwhat effect acid may haveon crops and trees.

Suggested alternative main activitiesActivity

Textbook G1

Activity G1a Practical

Learningobjectivessee above

i and ii

iii

Description

Teacher-led explanation and questioning OR Pupils work individually,in pairs or in small groups through the in-text questions and thenonto the end-of-spread questions if time allows.

Test your soil Pupils find out by experiment whether the soil fromthe school garden is acidic, alkaline or neutral.

Approx. timing

20 min

30 min

Target group

C H E S

R/G G R S

✔

Learning outcomes

Most pupils will ...

• understand what is meant by theenvironment

• appreciate that it may be polluted byhuman activities

• understand how soil forms.

Some pupils, making less progress will ...

• know that the land, sea and air are sometimespolluted.

Some pupils, making more progress will ...

• appreciate the vital importance of the soil.

Key wordspollution

Out-of-lesson learningHomework G1Textbook G1 end-of-spread questions


G2Lesson

planning guideAcid rain


Learning objectivesi Know what acid rain is.ii Recognise that acid rain has both human and ‘natural’ causes.

Scientific enquiryiii Observe patterns in data. (Framework YTO Sc1 9f)iv Identify and explain strengths and weaknesses in the evidence. (Framework YTO Sc1 9g)


Review learning

Pupils arrange cardsshowing the processes andequations involved in theformation of acid rain. Theyarrange them in the correctorder to make a flow chart.

Sharing responses

Pupils work in groups toprepare a short account oftheir finding from ActivityG2a.

Group feedback

Pupils work in groups tolook at results from ActivityG2b and brainstorm thequestion ‘How did acidityget into this water?’

Word game

Pupils check their progressso far in this unit by sortingcards into two sets: thingsthat are to do with acidrain and things that are notconnected with acid rain.

Looking ahead

In groups, pupils suggestwhat else, apart fromplants, may be affected byacid rain.


Textbook G2


Activity G2b Practical


i and ii

iii and iv

iii

Description


Acid rain and plants Pupils find out by experiment how acid rainaffects the growth of plants.

Take a rain check Pupils collect samples of rainwater, and watersamples from as many different local sources as possible. They testthe pH with universal indicator paper.

Approx. timing

20 min

20 min

20 min

Target group

C H E S

R/G G R S

✔

✔ (✔)

Key wordsacid rain


Learning outcomes


• understand that acid rain has both humanand ‘natural’ causes

• know the basic chemical reaction thatoccurs when acid rain forms.


• know some of the problems that acid rain cancause.


• appreciate the wider range of problems causedby ‘acid gases’ from car exhausts.


Recap last lesson

Wordsearch of termsassociated with soil, plantsand acidity.

Share learningobjectives

• Describe what acid rain is.• Identify the causes of

acid rain.• Observe patterns in data.

(Sc1)• Identify and explain

strengths and weaknessesin the evidence. (Sc1)

Problem solving

Show pupils slides orphotos, e.g. volcanoes,vehicles, factory chimneys, etc.Catalyst InteractivePresentations 3

Capture interest (1)

Demonstrate testing ofthree samples of waterusing universal indicatorand pH meter.


Show slides or photos ofrooftops of houses in thecountryside, with lichengrowing on them, androoftops in towns, withoutlichen. Catalyst InteractivePresentations 3


G2Lesson

planning guideInvestigate: What makesrainwater acidic?


Learning objectivesi Investigate what makes acidic rainwater.

Scientific enquiryii Describe patterns in data: use scientific knowledge and understanding to interpret the patterns, make prediction and check reliability.

(Framework YTO Sc1 9f)iii Describe how evidence supports or does not support a conclusion in their own or others’ enquiries; identify the limitations of data in

conclusions. (Framework YTO Sc1 9g)


Review learning

Lead a discussion comparing pupils’predictions with their conclusions.

Group feedback

Groups present their ideas aboutthe data as a short written report.

Analysing

Ask a volunteer from each group toreport the patterns they have foundin their data for class discussion.

Evaluating

Groups report their ideas of validityand reliability of their conclusionsfor class discussion.

InvestigationActivity

Activity G2c Discussion


i, ii and iii

Description

What makes rainwater acidic? Pupils study data about acid rain tofind out what factors have an effect on how acidic the rain becomes.

Approx. timing

40 min

Target group

C H E S

✔

Learning outcomes


• make effective use of secondary sources ofinformation

• identify and describe possible sources ofinformation and select from theseappropriate evidence, identifying somestrengths and weaknesses in evidence.


• select information from secondary sources• describe some possible sources of evidence.


• identify and explain the strengths andweaknesses of the evidence from secondarysources.


Setting the context

Pupils work in groups todecide why it is importantto gather data aboutrainwater pH, and what usecould be made of this data.

Introduce the apparatus

Demonstrate the use ofindicator paper and a pHmeter for measuring waterpH.

Safety

Pupils work in groups tosuggest ways to collect andtest water, and the safetymeasures needed.

Brainstorming (1)

Pupils work in groups tobrainstorm the question‘What might affect the pHof rainwater that falls inone particular place?’

Brainstorming (2)

Pupils work in groups tobrainstorm the question‘How will we get theinformation to decide whichthings affect the pH ofrainwater?’


G3Lesson

planning guideMore about acid rain


Learning objectivesi Acid rain causes a number of problems.ii Scientists monitor air and water pollution.iii How science can help to overcome some of these problems.

Scientific enquiryiv Investigating patterns in data. (red only)v Describe some positive and negative effects of scientific and technological developments. (Framework YTO Sc1 9a)


Textbook G3


Activity G3b Paper

Activity G3c Paper


i, ii, iii andiv

i

i

ii, iii and v

Description


Acid, metal and rock Pupils drip very dilute sulphuric acid on samples of metals and rocks to find the effect of acid rain.

Acid rain eats away Pupils find out by reading an article how acid rain continues to affect the environment despite attempts to clean up the air.

Job hunting Pupils engage in a letter-writing activity based on anenvironmental topic to develop literacy skills and raise awareness ofscience-related careers.

Approx. timing

20 min

30 min

25 min

20 min

Target group

C H E S

R/G G R S

✔ ✔

✔

✔

Key wordsmonitoring, red only: catalytic converter

Out-of-lesson learningHomework G3Textbook G3 end-of-spread questionsActivity G3bActivity G3c

Learning outcomes


• understand the basic chemistry of acid rainproblems

• appreciate the science of some of thesolutions to acid rain.


• appreciate that acid rain can damage theenvironment.


• appreciate how pollution problems like this aremonitored using sensors.


Recap last lesson

Wordsearch for causes ofacid rain.


• Explain what problems arecaused by acid rain.

• Describe the role ofscientists in monitoring andsolving this problem.

• Investigate patterns indata. (Sc1)

Problem solving

Pupils work in groups toput some locations inorder of how quickly astatue would corrode ineach location.

Brainstorming

Show pupils slides or photosof granite boulders that havebeen above the ground andthose that have been belowthe ground.Catalyst InteractivePresentations 3

Capture interest

An Internet pollutionmonitoring activity.Pollution in differentlocations can be compared.


Review learning

Show slides or photos oflimestone caves. In groups,pupils decide how the caveswere formed. Catalyst InteractivePresentations 3

Sharing responses

Each group of pupilsprepares a report on one ofthe jobs in Activity G3c.Each group reports back tothe class on the impact ofthat job on acid rain.

Group feedback

Groups of pupils report tothe class on their resultsand conclusions fromActivity G3a.

Word game

Pupils match cards, eachwith a different problemconcerned with acid rain, toa solution for the problem,and explain why. Pupils orgroups report ideas to class.

Looking ahead

Show a video of hurricanes,floods, deserts, etc. Suggestthat these extremes ofweather seem to beincreasing. Catalyst InteractivePresentations 3


G4Lesson

planning guideGlobal warming



Recap last lesson

Pupils list sources of acidrain and ways that acid rainfrom each source can bereduced.

Learning objectivesi Know about the greenhouse effect.ii Appreciate how carbon dioxide in the air might increase the greenhouse effect and so lead to global warming.

Scientific enquiryiii Consider data and draw conclusions as to positive or negative outcomes.iv Select information from secondary sources. (Framework YTO Sc1 8d)

Learning outcomes


• Describe what thegreenhouse effect is.

• Link the significance ofcarbon dioxide emissions tothe greenhouse effect andglobal warming.

• Consider data and drawconclusions. (Sc1)

• Select information fromsecondary sources. (Sc1)

Problem solving

Pupils work in groups tolabel a simplified carboncycle. This leads in toActivity G4a.

Brainstorming

Pupils set up a ‘grow yourown greenhouse effect’ on awindow sill at the start ofthe lesson, and makepredictions. They look atthe results in a plenary atthe end of the lesson.

Capture interest

Animation of carbon dioxideproduced by a burningcandle causing limewater toturn milky. Catalyst InteractivePresentations 3


Textbook G4

Activity G4a Paper

Activity G4b ICT


i and ii

i and ii

iii and iv

Description


Slowing global warming Pupils look at global warming and how toreduce it.

Research on global warming Internet research on greenhouse effectand global warming.

Approx. timing

20 min

20 min

30 min

Target group

C H E S

R/G G R S

✔

✔

Key wordsgreenhouse effect, global warming



• understand the greenhouse effect• appreciate the possible link between fossil

fuels, atmospheric carbon dioxide and globalwarming.


• understand the greenhouse effect.


• investigate the carbon dioxide/globalwarming link further.


Review learning

Pupils match wordsassociated with globalwarming with theirdefinitions.

Sharing responses

Pupils present their answersto Activity G4b to the classfor discussion.

Group feedback

In groups, pupils compareresults and predictions forthe ‘grow your owngreenhouse effect’suggested for Starter G4.

Word game

Crossword puzzle usingwords associated withpollution.

Looking back

Pupils revise andconsolidate knowledge fromthe unit.


G5Lesson

planning guideLooking at the evidence – Thinkabout the strength of theevidence



Bridging to the unit

Pupils brainstorm the question ‘Why have we kept records oftemperature readings going backfor over 100 years?’

Learning objectivesi Look at some of the evidence for the carbon dioxide/global warming link.The structure of this lesson is based around the CASE approach. The starter activities give concrete preparation. The main activities move away from theconcrete towards a challenging situation, where pupils need to think. The extended plenary gives pupils time to discuss what they have learnt, tonegotiate a method to commit to paper and express their ideas verbally to the rest of the class.

Scientific enquiryii Describe and interpret patterns in data. (Framework YTO Sc1 9f)iii Explain any anomalous results. (Framework YTO Sc1 8g)

Learning outcomes

Setting the context

Pupils work in groups to recordtheir recollections of weatherextremes (e.g. hottest day, coldestday, wettest month, strongestwind).

Concrete preparation (1)

Pupils analyse temperatureobservations taken in the schoolgrounds at the same time each dayfor 1 week/1 month.


Show a video of the damage causedby windstorms in the UK in October1987, January 1990 and October2002.Catalyst Interactive Presentations 3


Textbook G5

Activity G5a Discussion

Activity G5b Paper


i

i

ii and iii

Description


Weather forecast Pupils find out what data is recorded bymeteorologists and how this information is used.

Evidence for global warming Pupils study some data about changesin climate over the past 1000 years in order to decide whether thisshows evidence of global warming.

Approx. timing

30 min

15 min

25 min

Target group

C H E S

R/G G R S

✔

✔

Key wordsanomaly

Out-of-lesson learningTextbook G5 end-of-spread questionsActivity G5b


• appreciate the apparent link between carbondioxide levels and average global temperatureover the last 200 years

• appreciate that the picture appears morecomplex if viewed over a longer time period.


• understand that the Earth has got warmerover the last 200 years as we have burnt ourfossil fuels.


• have the opportunity to analyse data from awider range of sources/time periods and drawtheir own conclusions.


Group feedback

Groups of pupils present their ideas from Activity G5b for classdiscussion. The extent of disagreement between scientists as to theexistence of global warming can be emphasised by reading out quotesfrom some scientists.

Bridging to other topics

Pupils describe and interpret patterns in data to discover that this data is open to various interpretations. A class discussion focuses on whyand how this data can be abused. Pupils suggest other areas of sciencewhere the interpretation of data is open to question, e.g. health/fooddata in nutrition.


G Unit mapEnvironmental chemistry


Copy the unit map and use these words to help you complete it.You may add words of your own too.

animalscarbon dioxidecarbon monoxidefishforest firesfossil fuelsgreenhouse effectmonitoringneutralisationnitrogen

oxygenplantspollutionrocksscientistssulphur dioxidetreesvolcanoesweathering

Environment

Air, water, soil What is acid rain?

Global warming andthe evidence

Causes andcures of acid

rain

Unitmaps.qxd 18-Jun-04 11:36 AM Page 7


G1 StartersEnvironmental chemistry

Introduce the unit� Either draw the outline of the unit map on the board then

ask pupils to give you words to add, saying where to addthem. Suggest some words yourself when necessary to keeppupils on the right track.

� Or give out the unit map and ask pupils to work in groupsdeciding how to add the listed words to the diagram. Thengo through it on the board as each group gives suggestions.

Share learning objectives� Ask pupils to write a list of FAQs they would put on a

website telling people about soil. Collect suggestions as awhole-class activity, steering pupils towards those related tothe objectives. Conclude by highlighting the questions youwant them to be able to answer at the end of the lesson.

Problem solving� Pupils look at slides or a video about sedimentation to

recap Units 8G and 8H.

� Ask what soil is made of, expecting the answer ‘rockfragments’.

� Ask what else there is in soil (remains of plants andanimals forming humus).

� Ask pupils to suggest how soil has been formed from therock fragments.

Brainstorming� Pupils work in groups to brainstorm the question ‘Where

might soil pollution come from?’

� Each group in turn reports their ideas back to the class fordiscussion.

� The important points are listed on the board.

Capture interest� Pupils look at slides or a video of different habitats with

different plants growing in each one.

� Ask pupils why each habitat has different types of plants.

� Elicit ideas of different climate and different soilconditions.

� Introduce ideas about the effect of pollution on plants.

➔ Unit map

➔ Catalyst Interactive Presentations 3



Introduce the unit

Unit map forEnvironmental chemistry.


• Describe how soil can bepolluted.

• Explain how soil forms.• Use secondary sources of

information. (Sc1)

Problem solving

Show slides or a video clipabout sedimentation.Catalyst InteractivePresentations 3

Brainstorming

In groups, pupilsbrainstorm the question‘Where might soilpollution come from?’

Capture interest

Show slides or a video clip ofdifferent habitats, withdifferent ranges of plantsgrowing in each one. Catalyst InteractivePresentations 3

G-Starters.qxd 17-May-04 6:49 PM Page 1


G2 StartersAcid rain

Recap last lesson� Ask pupils to complete the wordsearch on the Pupil sheet.

� Show the answers as an OHT for them to check theiranswers. Use the words on it to introduce the lesson.

Share learning objectives� Ask pupils to write a list of FAQs they would put on a

website telling people about acid rain. Collect suggestions asa whole-class activity, steering pupils towards those relatedto the objectives. Conclude by highlighting the questionsyou want them to be able to answer at the end of the lesson.

Problem solving� Pupils look at slides or photos of sources of pollution, e.g.

volcanoes, vehicles, factory chimneys, etc.

� Ask pupils which of these contribute to acid rain.

� Ask pupils why these things cause rain to be acidic.

� Lead a class discussion about which substances will dissolvein water to form acids.

� Emphasise the importance of sulphur dioxide and oxides ofnitrogen in the formation of acid rain.

Capture interest (1)� Pupils watch a demonstration of testing samples of water to

see if they are acidic.

� Test the acidity using universal indicator and a pH meter.

� Remind pupils of the pH scale.

Capture interest (2)� Pupils look at slides or photos showing the rooftops of

houses in the countryside, with lichen growing on them,and those in towns/cities, without lichen.

� Ask pupils to spot the difference.

� Ask pupils to suggest why there is a difference.

� Emphasise that lichen is a good indicator of air pollution.

➔ Pupil sheet


➔ Teacher and technician sheet



Recap last lesson

Wordsearch of termsassociated with soil,plants and acidity.


• Describe what acid rain is. • Identify the causes of acid rain.• Observe patterns in data. (Sc1)• Identify and explain strengths

and weaknesses in the evidence.(Sc1)

Problem solving

Show pupils slides or photos,e.g. volcanoes, vehicles,factory chimneys, etc. Catalyst InteractivePresentations 3


Demonstrate testing ofthree samples of waterusing universalindicator and pH meter.


Show slides or photos ofrooftops of houses in thecountryside, with lichengrowing on them, androoftops in towns, withoutlichen. Catalyst InteractivePresentations 3



Recap last lesson

The words in this list are all to do with soil, plants and acidity.Find each of the words in the word box.


acidity

deposition

pollution

hydrangea

minerals pH

alkali crops

rock

acid rain

fragments humus

F R A G M E N T S D

A O C Z I X G R P E

M C I T N B V B O P

H K D C E Q Y K R O

A C I D R A I N C S

L Q T I A L K A L I

P W Y D L X F E P T

H U M U S S N J U I

A E G N A R D Y H O

Q P O L L U T I O N




Teacher and technician sheet

Equipment

� three samples of water at different pH values (one neutral, other two acidic)� test tubes� dropper� universal indicator solution� universal indicator paper� colour chart for universal indicator� pH meter

For the demonstration:

1 Pour a little of the first water sample into a test tube.

2 Add a few drops of universal indicator.

3 Use the colour chart to find the pH of the water sample.

4 Repeat the test for each of the other water samples.

5 Repeat the test for each water sample, but this time by dipping the universalindicator paper into a fresh portion of each water sample.

6 Test a fresh portion of each water sample using a pH meter.




G2 StartersInvestigate: What makesrainwater acidic?

Setting the context� Pupils work in groups to decide why it is important to gather data about rainwater pH.

� Each group reports their ideas to the whole class for discussion.

� Lead the discussion to include ideas of the damage caused to the environment byacid rain, use of data by pressure groups, use of monitoring by government agencies,influence on new legislation about emissions (quote introduction of catalyticconverters in cars).

Introduce the apparatus� Pupils watch a demonstration of the use of indicator paper and a pH meter for

measuring pH.

� Ask pupils about the advantages and disadvantages of each method.

Safety� Get pupils to work in pairs to think about how they would collect samples of

rainwater and test them for acidity.

� Ask pupils to list the hazards involved in this investigation. Pupils then decide howto minimise the danger presented by each hazard.

� Pairs report back to a class discussion, during which a final set of safety proceduresis listed on the board.

Brainstorming (1)� Pupils work in groups to brainstorm the question ‘What might affect the pH of

rainwater that falls in one particular place?’

� Groups report back their ideas to the whole class for discussion.

� Pupils will suggest things like ‘How much sulphur dioxide there is in the air’. Askthem what will affect this.

� Elicit ideas of location near to power stations, motorways, factories, etc.

� Elicit ideas of how weather conditions might affect the pH of rainwater. Ask ifheavy rain is likely to have a different pH to light rain.

� Write a list of the things that might affect the pH of rainwater on the board.

Brainstorming (2)� Pupils work in groups to brainstorm the question ‘How will we get the information

to decide which things affect the pH of rainwater?’

� Groups report back their ideas to the class for discussion.

� Elicit ideas of getting results from many locations, repeating results, etc.

� Lead this discussion to the idea that gathering sufficient data would take moretime than will be available.

� Introduce the idea of secondary data.

� Ask pupils where they might be able to get such data from.

➔ Teacher andtechniciansheet


Setting the context

Pupils work in groups todecide why it is importantto gather data aboutrainwater pH, and what usecould be made of this data.


Demonstrate the use ofindicator paper and a pHmeter for measuring water pH.

Safety

Pupils work in groupsto suggest ways tocollect and test water,and the safetymeasures needed.

Brainstorming (1)

Pupils work in groups tobrainstorm the question‘What might affect the pHof rainwater that falls inone particular place?’

Brainstorming (2)

Pupils work in groups tobrainstorm the question ‘Howwill we get the information todecide which things affect thepH of rainwater?’


G2 StartersInvestigate: What makesrainwater acidic?


Teacher and technician sheet

Equipment

� samples of water at different pH values (one neutral, one acidic,one alkaline)

� test tubes� dropper� universal indicator paper� colour chart for universal indicator� pH meter

For the demonstration:

1 Pour a little of the first water sample into a test tube.

2 Dip universal indicator paper into the water.

3 Use the colour chart to find the pH of the water sample.

4 Repeat the test for each of the other water samples.

5 Test a fresh portion of each water sample using a pH meter.




G3 StartersMore about acid rain

Recap last lesson� Ask pupils to complete the wordsearch on the Pupil sheet.

� Show the answers as an OHT for them to check their answers. Use thewords on it to introduce the lesson.

Share learning objectives� Write the learning objectives on the board and show why it is important

that we know about these ideas.

� Tell pupils that acid rain causes problems.

� Give pupils examples of the problems, e.g. corrosion of statues andbuildings, corrosion of metals, death of trees and fish.

� Tell pupils that scientists monitor the acidity of water and air in differentlocations.

� Ask pupils why it is important that this monitoring is carried out.

Problem solving� Pupils look at a worksheet describing several different locations. They think

about the corrosion of a statue by acid rain in each location.

� They use ideas about acid rain to put these locations in order, from mostquickly corroded to least quickly corroded statue.

� Ask volunteers to report ideas for class discussion.

Brainstorming� Pupils look at slides or photos of granite boulders that have been above

ground and those that have been below ground.

� Ask pupils to compare how much the boulders have weathered.

� Pupils work in groups to brainstorm the question ‘Why have the bouldersweathered differently?’

� Groups report their ideas for class discussion.

Capture interest� Pupils use the Internet to access data from roadside air monitoring stations.

� They follow instructions on the worksheet to access data from The UKNational Air Quality Information Archive.

� They can compare pollution from monitoring stations in differentlocations.

� They can look at a variety of data, e.g. carbon monoxide, oxides of nitrogen,ozone, particles, sulphur dioxide.

➔ Pupil sheet

➔ Pupil sheet

AnswersOrder of locations fromquickest to slowestcorrosion: E C A B D

➔ Catalyst InteractivePresentations 3

➔ Pupil sheet


Recap last lesson

Wordsearch forcauses of acid rain.


• Explain what problems are caused byacid rain.

• Describe the role of scientists inmonitoring and solving this problem.

• Investigate patterns in data. (Sc1)

Problem solving

Pupils work in groupsto put some locationsin order of how quicklya statue would corrodein each location.

Brainstorming

Show pupils slides or photos ofgranite boulders that have beenabove the ground and those thathave been below the ground. Catalyst Interactive Presentations 3

Capture interest

An Internet pollutionmonitoring activity.Pollution in differentlocations can becompared.


http://www.heinemann.co.uk/hotlinks/url.asp?urlid=9595



Recap last lesson

The words in this list are all to do with the causes of acid rain.Find each of the words in the word box.


acid rain fuel

train

nitrogen oxides

oil sulphur

exhaust gas factory

volcano

car

fumes lorry

E N I T R O G E N O

X A H P C L E U F X

H C N T A F W O U I

A C I D R A I N M D

U N A U S C X A E E

S J R Y Q T K C S S

T R T F X O N L B E

G D L C A R V O I L

A L O R R Y R V G T

S U L P H U R O Z M



Problem solving

1 Below are descriptions of several places in the UnitedKingdom.Read the description of the first place carefully.

2 Decide how likely it is that a statue in this place will becorroded by acid rain. You may like to give the place a scoreout or 10, with 10/10 being the quickest corrosion and 1/10the slowest.

3 Repeat this for each place.

4 Now put the places in order, from where you think the statuewill corrode the quickest, to where you think corrosion will beslowest.

Places

A This is a park in the middle of a town. The park is surroundedby busy roads. There are lots of shops in the town, but nofactories.

B This is a garden at the back of a house on the edge of thetown. The house is in a quiet street, surrounded by lots ofother houses.

C This is a garden at the back of a house in a large industrial city.The house is in an area containing lots of factories and busyroads.

D This is a field in the countryside. It is surrounded by quietroads and other fields.

E This is the car park of an office building. It is surrounded byfactories and busy roads. Opposite the office building is an oil-burning power station.




Capture interest

You are going to use the instructions on this worksheet to accessdata about air pollution from roadside air monitoring stations inthe United Kingdom.

1 Log onto the website of The UK National Air QualityInformation Archive.

2 A UK map is shown, divided into areas.Click on any map area, e.g. West Midlands.

3 You will be given a window showing an Air Quality Summary.Find where it says ‘For More Information’ and below this clickon ‘CLICK HERE’.

4 You will now see a more detailed map of the area you havechosen, showing the location of air monitoring sites in thisarea.

5 Click on a site location, e.g. for the West Midlands area youcould choose ‘Wolverhampton Centre’.

6 Choose ‘Site Information’ and then click ‘Submit’ to get adescription and photos of the location.

7 You can also go back and choose what sort of data you wantto see, e.g. ‘Weekly Graphs’, then click ‘Submit’.You will see a series of graphs showing pollution by carbonmonoxide, oxides of nitrogen, ozone, particles and sulphurdioxide, over the past week.

8 Choose ‘Last Hour’s Data’ and click ‘Submit’ to see the mostrecent levels of pollutants in this location.

9 Go back to the area map and select other site locations.Compare the pollution levels in different locations within the same area.

10 Go back to the UK map and choose another area.Compare pollution levels in different areas of the UK.






G4 StartersGlobal warming

Recap last lesson� Pupils work in groups to list different sources of acid rain.

� For each source of acid rain, pupils list ways that this couldbe reduced.

� Groups report their ideas for class discussion.

� Ideas are listed on the board.

Share learning objectives� Ask pupils to write a list of FAQs they would put on a website

telling people about global warming. Collect suggestions as awhole-class activity, steering pupils towards those related tothe objectives. Conclude by highlighting the questions youwant them to be able to answer at the end of the lesson.

Problem solving� Pupils use a list of words to label a simple diagram of the

carbon cycle.

� When the diagram is complete pupils should be able to seewhat the sources of carbon dioxide are.

Capture interest (1)� Set up a demonstration ‘grow your own greenhouse effect’.

� Pupils predict what results they expect to observe by the endof the lesson.

� They record the results for use in a plenary activity.

Capture interest (2)� Pupils watch a demonstration to show that carbon dioxide

and water are the products of combustion of a candle, oruse the animation of the experiment in Catalyst InteractivePresentations 3.

� Show them that a gas that turns limewater cloudy isproduced. Ask what this shows.

� Show them that a colourless liquid is produced. Tell them thatthis is water. (This can be tested using anhydrous copper(II)sulphate if desired.) Explain that water is not a pollutant.

� Lead them to ideas that all fuels obtained from oil andnatural gas have the same combustion products as thecandle, and therefore all of these fuels produce carbondioxide when burned.

➔ Pupil sheet

➔ Pupil sheet

Equipmentglass jar or plastic propagator;computer; interface with twotemperature probes; stand and twoclamps; access to a sunny window sill

➔ Teacher and technician sheet



Recap last lesson

Pupils list sources ofacid rain and ways thatacid rain from eachsource can be reduced.


• Describe what the greenhouse effect is. • Link the significance of carbon dioxide

emissions to the greenhouse effect andglobal warming.

• Consider data and draw conclusions.(Sc1)

• Select information from secondarysources. (Sc1)

Problem solving

Pupils work in groups tolabel a simplified carboncycle. This leads in to ActivityG4a.


Pupils set up a ‘grow yourown greenhouse effect’experiment on a windowsill at the start of thelesson, and makepredictions. They look atthe results in a plenary atthe end of the lesson.


Animation of carbondioxide produced by aburning candle causinglimewater to turn milky.Catalyst InteractivePresentations 3



Problem solving

Use these words to label the arrows in the diagram.You may use some of the words more than once.

burning feeding partial decompositiondeath photosynthesisdecay respiration


carbon dioxide in the air

carbon in animals

carbon in plants

carbon in fossil fuels

carbon in dead animals and plants




You are going to investigate whether the glass of a greenhousereally helps to keep the heat energy inside.

In this activity, a glass jar on a sunny window sill represents thegreenhouse. Temperature sensors measure the temperature insideand outside the jar.

The experiment will be set up like this:

1 Predict whether it will be hotter or colder inside the jar thanoutside by the end of the lesson, and say why.

2 Record the temperature inside and outside the jar immediatelyafter you set the apparatus up, and again at the end of thelesson. (You could use a printout from the computer.)

3 Keep your results for use in a plenary activity.


computerinterfacejarclamp stand

temperature sensors



Capture interest (2)Teacher and technician sheet

Equipment

� glass filter funnel� U-tube� side arm tube� connecting glass tubing� pump� candle� limewater� trough� ice

1 Set up the apparatus as shown in the diagram.

2 Start the pump and then light the candle.3 Point out to pupils that the limewater goes cloudy after a short time.4 After several minutes extinguish the candle, turn off the pump and remove

the U-tube to show pupils the water that has condensed there.


limewater

glasstube

glassfunnel

U-tube

rubbertubing

topump

candle

ice



G5 StartersLooking at the evidence –Think about

Bridging to the unit� Pupils work in groups to brainstorm the question ‘Why have we kept

records of temperature readings going back for over 100 years?’

� Groups report their ideas to the class for discussion.

� Lead the discussion to ideas about long-term trends in climate change.

Setting the context� Pupils work in groups to write down their recollections of weather

extremes.

� Groups report back their ideas so they can be listed on the board.

� Emphasise the unreliability of memory, and the need to keep records.

� Also point out the short length of memory (perhaps 70 years) for oneperson.

Concrete preparation (1)� Give pupils temperature observations taken in the school grounds at

the same time each day over a period of time (1 week/1 month). Note:these measurements must be taken in advance of the lesson.

� Pupils work in groups to decide whether anything can be concludedabout weather patterns from this data.

� Groups report their ideas for class discussion, leading to the conclusionthat this data is over too short a period of time to draw meaningfulconclusions.

� Also elicit ideas that observations would need to be from more thanone location.

Concrete preparation (2)� Pupils look at a video of the damage caused by windstorms in the UK.

� Tell pupils that severe windstorms struck the UK in October 1987,January 1990 and October 2002.

� Ask pupils to work in groups to decide whether this data proves thatweather extremes in the UK are increasing, and what more informationmight be needed to make this conclusion.

� Groups report back ideas for class discussion.

� Inform groups that severe windstorms have also struck the UK manytimes in the past. Reports of severe weather go back several centuries.Records kept for the last 100 years show that recent storms are noworse than those many years ago. Ask them whether this informationmakes a difference to their conclusions.



Bridging to the unit

Pupils brainstorm the question ‘Why have we kept records oftemperature readings going backfor over 100 years?’

Setting the context

Pupils work in groups to record theirrecollections of weather extremes(e.g. hottest day, coldest day,wettest month, strongest wind).


Pupils analyse temperatureobservations taken in the schoolgrounds at the same time eachday for 1 week/1 month.


Show a video of the damage caused bywindstorms in the UK in October 1987,January 1990 and October 2002.Catalyst Interactive Presentations 3


G1aTeacher

activity notesTest your soil

Running the activityPupils work in groups of two or three, following the instructions on theActivity sheet.

They shake a sample of dry garden soil with distilled water, centrifuge and adduniversal indicator solution. Universal indicator is added to distilled water in asecond tube as a control.

Pupils use a colour chart for the indicator to find the pH of the soil.

Other relevant materialGardening reference books

Skill sheet 4: Web searches

Expected outcomesPupils will find out by experiment whether the soil from the school garden isacidic, alkaline or neutral.

PitfallsIf no school garden is available, soil may be taken from any convenient source,or pupils could be asked to bring soil samples from their own gardens.

Safety notesEye protection should be worn.

Pupils should wash their hands afterwards.

Do not collect soil from any area known to be contaminated with dog faeces.

ICT opportunitiesSearch the Internet using the key words: soil, acidity, alkalinity.

Answers1 (depends on results)

2 Water without soil was tested as a control experiment to check forcontamination and confirm that any acidic or alkaline substances havecome from the soil and not the water.

3 No. Soil from only one place in the garden was tested.

4 Test soil samples from several different parts of the garden.

5 If the soil test is acidic, lime could be added because most plants do notgrow well in acidic soil. If the soil is alkaline, peat could be added. Notreatment if the acidity or alkalinity is right for the plants growing there.


Type Purpose DifferentiationPractical Pupils find out by experiment whether the soil from the school garden is acidic,

alkaline or neutral.Core

G-Teachers.qxd 17-May-04 8:07 PM Page 1

G1aTechnician

activity notesTest your soil

EquipmentFor each group:

� two centrifuge tubes� universal indicator solution� dry soil sample� access to a centrifuge� indicator colour chart

Other relevant materialGardening reference books

Skill sheet 4: Web searches

For your informationRunning the activityPupils work in groups of two or three, following the instructions on theActivity sheet.

They shake a sample of dry garden soil with distilled water, centrifuge and adduniversal indicator solution. Universal indicator is added to distilled water in asecond tube as a control.

Pupils use a colour chart for the indicator to find the pH of the soil.

Expected outcomesPupils will find out by experiment whether the soil from the school garden isacidic, alkaline or neutral.

PitfallsIf no school garden is available, soil may be taken from any convenient source,or pupils could be asked to bring soil samples from their own gardens.

Safety notesEye protection should be worn.

Pupils should wash their hands afterwards.

Do not collect soil from any area known to be contaminated with dog faeces.

ICT opportunitiesSearch the Internet using the key words: soil, acidity, alkalinity.


Type Description DifferentiationPractical Pupils find out by experiment whether the soil from the school garden is acidic,

alkaline or neutral.Core

G-Technician.qxd 28-Apr-04 10:49 AM Page 1

G1aActivity

CoreTest your soil

In this activity, you are going to test the soil from the schoolgarden to check whether it is acidic, alkaline or neutral.

Obtaining evidence

1 Half-fill the sample tube with drysoil from the school garden.

2 Add distilled water to the tube untilit is three-quarters full.

3 Shake the tube well for 30 seconds.4 Take the tube to your teacher to be

centrifuged.5 Add distilled water to a second tube

until it is three-quarters full.6 Add 3 drops of universal indicator

solution to each tube. Any acidic oralkaline substances that havedissolved in the water from the soilwill change the colour of theindicator.

7 The second tube is a control. Use the second tube to check forcontamination and confirm thatany acidic or alkaline substanceshave come from the soil and notthe water.

8 Use an indicator colour chart to findout the pH of your soil sample.

Considering the evidence

1 Is the soil acidic, alkaline or neutral?2 Explain why you also tested the

water without the soil.

Evaluating

3 Do you think that this is a reliable test of the pH of the soil in the whole of this garden? Explain your answer.

4 What further work would you do to make the results more reliable?

5 Would you recommend any treatment for this soil? If so, what?


test with universal indicator

soil

tube 2

centrifuge

shake

tube 1

water

soil

water

Wear eyeprotection.

Wash yourhandsafterwards.

G-Activities.qxd 17-May-04 6:52 PM Page 1

G2aTeacher

activity notesAcid rain and plants

Running the activityPupils place cress seedlings in plastic bags, one with ‘acid rain’ (sodiummetabisulphite solution) and another with distilled water, seal the bags andleave them for 1 week. The best position for this is on a window sill in thelaboratory. Pupils then compare the growth of the cress seedlings.

Pupils should work in groups of two or three, following the instructions on theActivity sheet. They are given a method and prompted to make observations,draw conclusions and evaluate.

Expected outcomesPupils will see that acid rain adversely affects the growth of plants.

Safety notesEye protection should be worn until the bags are sealed. Sulphur dioxidesolution is not suitable. Sodium metabisulphite solution is a less harmfulalternative but asthmatics should be warned not to inhale any vapour.Refer to Hazcards or similar sources for details of risk assessment.

ICT opportunitiesSearch the Internet for information about acid rain.

Answers1 Dying/leaves yellow/seedlings collapsed/death.

2 This was a control, to show that the seedlings were affected by the acidrain, not some other cause.

3 Yes, because the same number of seeds and same conditions were used foreach experiment. No, because the volumes of water and ‘acid rain’ were notmeasured.

4 Use staple food seeds for the experiment instead of cress (e.g. wheat orcorn); set up an experiment out in the field – collect rain samples, measurerain pH, measure soil pH, compare with an area where rain is not as acidic.


Type Purpose DifferentiationPractical Pupils find out by experiment how acid rain affects the growth of plants. Core


G2aTechnician

activity notesAcid rain and plants


� cotton wool� two polythene bags� two Petri dishes of cress seedlings� two elastic bands� two Petri dish lids� two sticky labels� sodium metabisulphite solution� two dropping pipettes labelled ‘acid rain’� distilled waterCress seeds will need to be sown a few days in advance of the lesson.

For your informationRunning the activityPupils place cress seedlings in plastic bags, one with ‘acid rain’ (sodiummetabisulphite solution) and another with distilled water, seal the bags andleave them for 1 week. The best position for this is on a window sill in thelaboratory. Pupils then compare the growth of the cress seedlings.

Pupils should work in groups of two or three, following the instructions on theActivity sheet. They are given a method and prompted to make observations,draw conclusions and evaluate.

Expected outcomesPupils will see that acid rain adversely affects the growth of plants.

Safety notesEye protection should be worn. Sulphur dioxide solution is not suitable.Sodium metabisulphite solution is a less harmful alternative but asthmaticsshould be warned not to inhale any vapour.Refer to Hazcards or similar sources for details of risk assessment.



Type Purpose DifferentiationPractical Pupils find out by experiment how acid rain affects the growth of plants. Core


G2aActivity

CoreAcid rain and plants

Sulphur dioxide is a gas produced whenever fossil fuels areburned. Volcanoes can also produce sulphur dioxide whenthey erupt. Sulphur dioxide dissolves in rain, making acid rain.You are going to find out how acid rain affects plants.

Obtaining evidence

1 Take two dishes of cress seedlings.2 Put one dish inside a polythene bag labelled ‘acid rain’ and the

other inside a bag labelled ‘pure water’.3 Put some cotton wool in a Petri dish lid. Soak this cotton wool

with ‘acid rain’. Put this Petri dish inside the bag labelled ‘acidrain’.

4 Put some more cotton wool in another Petri dish lid. Soak thiscotton wool with water. Put this Petri dish inside the baglabelled ‘pure water’.

5 Seal each bag with an elastic band around the top.6 Observe your seedlings after a few days.7 Record your observations in a table.


1 How did the ‘acid rain’ affect the cress seedlings?2 What was the purpose of using a second sample of cress

seedlings with cotton wool soaked in water instead of acidrain?

Evaluating

3 Was this experiment a fair test? Explain your answer.4 How could you improve this experiment to get a better idea of

how acid rain might affect our food crops?


Wear eyeprotection.

Take carewith ‘acidrain’ solution

– it contains harmfulsulphur dioxide.cotton wool

soaked in'acid rain'

cotton woolsoaked inwater

cress seedlingscress seedlings

sealed plastic bags


G2bTeacher

activity notesTake a rain check

Running the activityPupils work in small groups of two or three. Advance planning will be required if pupils are to collect theirown water samples. Alternatively, these may be collected and labelled up by the teacher or technician.

Pupils collect samples of rainwater, and water samples from as many different local sources as possible.They test the pH with universal indicator paper.

Core: The activity gives pupils the opportunity to make and record observations and to analyse andconclude.

Extension: Pupils also use a pH meter.

Other relevant materialTo demonstrate how burning produces acidic gases, light a match and test the gases produced withuniversal indicator to simulate burning fuels. Put 4 drops of universal indicator solution into a test tube.Turn the tube around so that the indicator coats the inside. Clamp the test tube upside down. Light amatch and hold it under the tube so that the smoke rises. Note the pH.

Expected outcomesCore and Extension: Pupils will gain a greater understanding of the acid rain problem in relation to theirown environment.

PitfallsIn some areas acid rain may not be a problem and the results may seem uninteresting.

This can be overcome by supplying samples of ‘acidic rainwater’ from other areas.

Safety notesRefer to school and LEA policy and ensure parental consent, adequate supervision, etc. on visits to collectwater samples. Parental consent will not be required if the pond is on the same site as the school, but extrasupervision will be necessary. If the pond is anywhere other than the school site, even in the local park, itis an ‘off-site’ visit and parental consent etc. is required.

Plastic gloves should be worn.

Universal indicator solution is flammable.

ICT opportunitiesPupils could exchange results with pupils in other areas (contrasting environments) via the Internet.

AnswersCore:

1 (depends on results)

2 Explanations should include ideas of pollution from burning fuels.

3 The previous contents may have been acidic.

Extension:

4 The pH meter gave more precise pH values.


Type Purpose DifferentiationPractical Pupils collect samples of rainwater, and water samples from as many different local sources

as possible. They test the pH with universal indicator paper.Core (Extension)


G2bTechnician

activity notesTake a rain check

EquipmentFor each group: For the teacher demonstration:

� plastic drinks bottles (about 5) � box of matches� universal indicator paper (1 book) � universal indicator solution� scissors � test tube

� clamp stand and clamp

Other relevant materialTo demonstrate how burning produces acidic gases, light a match and test thegases produced with universal indicator to simulate burning fuels. Put 4 dropsof universal indicator solution into a test tube. Turn the tube around so thatthe indicator coats the inside. Clamp the test tube upside down. Light a matchand hold it under the tube so that the smoke rises. Note the pH.

For your informationRunning the activityPupils work in small groups of two or three. Advance planning will be requiredif pupils are to collect their own water samples. Alternatively, these may becollected and labelled up by the teacher or technician.

Pupils collect samples of rainwater, and samples from as many different localsources as possible. They test the pH with universal indicator paper.

Core: The activity gives pupils the opportunity to make and record observationsand to analyse and conclude.

Extension: Pupils also use a pH meter.

Expected outcomesCore and Extension: Pupils will gain a greater understanding of the acid rainproblem in relation to their own environment.

PitfallsIn some areas acid rain may not be a problem and the results may seemuninteresting.

This can be overcome by supplying samples of ‘rainwater’ from other areas.

Safety notesRefer to school and LEA policy and ensure parental consent, adequatesupervision, etc. on visits to collect water samples. Parental consent will not berequired if the pond is on the same site as the school, but extra supervision willbe necessary. If the pond is anywhere other than the school site, even in thelocal park, it is an ‘off-site’ visit and parental consent etc. is required.

Plastic gloves should be worn.

Universal indicator solution is flammable.

ICT opportunitiesPupils could exchange results with pupils in other areas (contrastingenvironments) via the Internet.


Type Purpose DifferentiationPractical Pupils collect samples of rainwater, and samples from as many different local sources as

possible. They test the pH with universal indicator paper.Core (Extension)


G2bActivity

CoreTake a rain check

In this activity, you are going to make a rain collector to find outwhether acid rain is a problem in the area where you live.

Equipment

For each group:� plastic drinks bottles (about 5)� universal indicator paper (1 book)� scissors

Obtaining evidence

1 Before you start the experiment, rinse all the drinks bottles several times with water.

2 Carefully cut off the top part of the bottleand turn it upside down to make a funnel, as shown in the diagram.

3 Place your rain collector firmly in the ground in a safe place.4 Use the cut off bottom ends of other drinks bottles to collect samples of water from

other places, for example a pond, a river, the sea, a canal, puddles, natural springsand the tap.

5 Test each of your water samples with universal indicator paper. To do this, dip a stripof universal indicator paper into the water sample. Observe the colour of the paperand compare this with the colour chart to find the pH of the water sample.

Presenting the results

6 Record your results in a table.


1 Were any of your water samples acidic?2 Try to explain any differences between the pH values of your water samples.

Evaluating

3 Why was it important to rinse the drinks bottles thoroughly at the start of thisexperiment?

Obtaining evidence

7 Use a pH meter or sensor to check the accuracy of your results.


4 How were the results given by the pH meter better than those given by the universalindicator paper?


Wear eyeprotection.

Take care whencollecting watersamples from

ponds, rivers, lakes, etc.Wear plastic gloves andwash your handsafterwards.

1.5 litredrinks bottle

cut put top partupside downto make a funnel

Extension


G2cTeacher

activity notesInvestigate: What makesrainwater acidic?

Running the activityPupils work in groups to predict what factors might affect the pH of rainwater.Each group presents ideas to the class for discussion.

Pupils use the Resource sheet to analyse acid rain data obtained from threelocations near a town. They answer questions about patterns in the data.

Other relevant materialG2c Resource sheet

PitfallsSome pupils will need guidance in the analysis of the data.

ICT opportunitiesPupils could search the Internet for data about acid rain.

Answers1 Wind direction, rainfall/heaviness of rain, location, amount of traffic on

motorway, output of power station.

2 � When the wind blows from the SW, fumes from the power station blowover location C, and fumes blow from the motorway over location A,causing the rain to be more acidic.

� When the wind blows from the NW, fumes from the town blow overlocation B, causing the rain to be more acidic.

� When the rain is heavier, the acidity is lower because the fumes aremore diluted in the larger volume of water.

3 The data were collected during a 9-month period. The locations were spreadaround the town, some distance from each other. Data can only becollected on days when it rains.

4 There are too few results for the data to be reliable.

5 Repeat and average results. Take results over longer periods of time thanone day in each month.

6 On the Internet/in government records, etc. This data is more reliablebecause it is measured by professionals rather than schoolchildren.


Type Purpose DifferentiationDiscussion Pupils study data about acid rain to find out what factors have an effect on how acidic

the rain becomes.Core Resource


G2cActivity

CoreInvestigate: What makesrainwater acidic?

You are going to study data about acid rain to find out whatfactors have an effect on how acidic the rain becomes.

Planning and predicting

1 Discuss with others in your group what might affect the pH ofrainwater.

2 Write down your ideas.3 Choose a spokesperson for your group to present your ideas to

the rest of the class.

Obtaining evidence

4 Look at the Resource sheet, then answer the questions below.

1 What things are affecting the acidity of the rainwater aroundthis town? Make a list.

2 What evidence can you find in the data to support your ideasfor each of the things on your list?

Evaluating

3 This data has been given to you. Why might it have beendifficult for you to get this sort of data in your owninvestigation?

4 How reliable is the data you have been given? Give reasons foryour answer.

5 How could the data be made more reliable?6 Where might you find more reliable data about acid rain?

Explain why this data is more reliable.



G2cActivityResourceInvestigate: What makes

rainwater acidic?Pupils from a secondary school monitored thepH of rain that fell in three locations aroundtheir town. These locations are marked A, Band C on the map.

The rain that fell on each of four individual days at different times of the year was collectedat each location. For each day, the depth ofrainfall and pH of the rainwater were measured.The pupils also made a note of the directionfrom which the wind was blowing and theweather on each day of rain collection.

Their results are shown below.


NNE

ESESSW

W

NW

town

motorway

oil-firedpowerstation

AC

B

Wind Weather Rainfall in Month direction description Location mm Rain pH

A 5 6.3

January NW light rain B 6 6.4

C 6 7.0

A 5 6.3

April SW showers B 5 7.0

C 6 5.0

A 24 6.6

July SW heavy rain B 23 7.0

C 25 5.7

A 24 6.7

October W heavy rain B 25 7.0

C 24 6.8


G3aTeacher

activity notesAcid, metal and rock

Running the activityCore and Extension: Pupils add very dilute sulphuric acid drop by drop to samples of metals and rocks. They look for evidence of a reaction and change of appearance of each sample.

Expected outcomesCore: Pupils discover that acid rain attacks some metals and rocks, causing erosion, but not others.

Extension: Pupils also have the opportunity to practice writing equations.

PitfallsUsing a very low concentration of acid, these reactions are quite slow. Pupils will need to be patient in order to observe changes.

Safety notesAlthough the acid is very dilute (0.005 mol dm–3), care should be taken that it does not get onto skin or clothes.

AnswersCore:

1 no

2 Zinc, iron, chalk and marble reacted with the acid.

3 Changed colour, became smaller.

4 Because acid rain contains very dilute sulphuric acid this experiment showed the effect of acid rain on metals and rocks well, but in reality the acid rain would be in contact with the rocks and metals for much longer than in the experiment.

5 Put metal and rock samples out in the rain for many weeks/months and periodically observe any changes.

Extension:

1 – 3 As core 1 – 3 .

4 calcium carbonate + sulphuric acid → calcium carbonate + carbon dioxide + waterCaCO3 + H2SO4 → CaSO4 + CO2 + H2O

5 zinc + sulphuric acid → zinc sulphate + hydrogenZn + H2SO4 → ZnSO4 + H2

6 – 7 As core 4 – 5 .


Type Purpose DifferentiationPractical Pupils drip very dilute sulphuric acid on samples of metals and rocks to find the effect

of acid rain.Core, Extension


G3aTechnician

activity notesAcid, metal and rock


� watch glasses� dropper� hand lens� very dilute sulphuric acid (0.005 mol dm–3)� small pieces of zinc, iron and lead� small pieces of chalk, marble and granite

For your informationRunning the activityCore and Extension: Pupils add very dilute sulphuric acid drop by drop tosamples of metals and rocks. They look for evidence of a reaction and change ofappearance of each sample.

Expected outcomesCore: Pupils discover that acid rain attacks some metals and rocks, causingerosion, but not others.

Extension: Pupils also have the opportunity to practice writing equations.

PitfallsUsing a very low concentration of acid, these reactions are quite slow. Pupilswill need to be patient in order to observe changes.

Safety notesAlthough the acid is very dilute (0.005 mol dm−3), care should be taken that itdoes not get onto skin or clothes.


Type Purpose DifferentiationPractical Pupils drip very dilute sulphuric acid on samples of metals and rocks to find the effect

of acid rain.Core, Extension


G3aActivity

CoreAcid, metal and rock

In this activity you are going to investigate the effect of acid rain on metals and rocks.

Equipment

For each group:� watch glasses � very dilute sulphuric acid� dropper � small pieces of zinc, iron and lead� hand lens � small pieces of chalk, marble and granite

Obtaining evidence

1 Collect a sample of a metal and place it on a watch glass.2 Observe the appearance of the sample.3 Use a dropper to add a few drops of very dilute sulphuric acid to the sample.4 Observe what happens to the sample. Look for evidence of a reaction: gas

given off; change in colour; change in shape. Use a hand lens to take a closelook at how the sample may have changed in appearance.

5 Repeat steps 1 to 4 using each of the other metal samples and each of the rock samples.




1 Did all the metals and rocks react with the acid?2 Make a list of the metals and rocks that did react with the acid.3 How did the metals and rocks that did react with the acid change in appearance?

Evaluating

4 This experiment used very dilute sulphuric acid. How well did this show you how acid rain would react with metals and rocks?

5 How could you find out if ‘real’ acid rain causes similar corrosion to metals and rocks?


Wear eyeprotection.

Acids arecorrosive.Wash your

hands afterwards.

metal orrock sample

dropper

sulphuric acid

watch glass


G3aActivity

ExtensionAcid, metal and rock

In this activity you are going to investigate the effect of acid rain on metals and rocks.

Equipment

For each group:� watch glasses � dropper� hand lens � very dilute sulphuric acid� small pieces of zinc, iron and lead� small pieces of chalk, marble and granite

Obtaining evidence

1 Collect a sample of a metal and place it on a watch glass.2 Observe the appearance of the sample.3 Use a dropper to add a few drops of very dilute sulphuric acid to the sample.4 Observe what happens to the sample. Look for evidence of a reaction: gas given off;

change in colour; change in shape. Use a hand lens to take a close look at how thesample may have changed in appearance.

5 Repeat steps 1 to 4 using each of the other metal samples and each of the rock samples.




1 Did all the metals and rocks react with the acid?2 Make a list of the metals and rocks that did react with the acid.3 How did the metals and rocks that did react with the acid change in appearance?4 Chalk is made of calcium carbonate. Copy and complete these equations for the

reaction of chalk with dilute sulphuric acid.

calcium carbonate + sulphuric acid → calcium +

carbon + water

CaCO3 + H2SO4 → 5 Copy and complete these equations for the reaction of zinc with dilute sulphuric acid.

zinc + sulphuric acid → zinc + hydrogen

Zn + H2SO4 →

Evaluating

6 This experiment used very dilute sulphuric acid. How well did this show you how acidrain would react with metals and rocks?

7 How could you find out if ‘real’ acid rain causes similar corrosion to metals and rocks?


Wear eyeprotection.

Acids arecorrosive.Wash your

hands afterwards.

metal orrock sample

dropper

sulphuric acid

watch glass


G3bTeacher

activity notesAcid rain eats away

Running the activityThis is a written task where pupils read an article about the effects of acid rainin northeastern USA (from an ENN web page, and given on the Resource sheet)and use the questions on the Activity sheet to help them interpret theinformation. It is best done individually.

Other relevant materialG3b Resource sheet


Answers1 The US federal General Accounting Office (GAO), in Vermont and

throughout northeastern USA.

2 Acid rain is continuing to damage ecosystems in the area studied.

3 Sulphur dioxide and nitrogen oxide.

4 Sulphur dioxide emissions have been reduced but nitrogen oxide emissionsremain unchanged.

5 To lessen the effects of acid (accept alternatives, e.g. cancel out/protect).

6 Increased in 48% of the lakes sampled.

7 Nitrogen oxides in the air dissolve in rainwater to produce nitrates that runoff the land into rivers and lakes.

8 Fish are unable to survive in acidified and nitrate-laden lakes. Acidified soilis stripped of nutrients that help plants survive cold temperatures.

9 Syrup production from maple trees is reduced. Fish farming might beaffected.

10 More stringent national regulation of all nitrogen oxide sources, forcingpower plants to modernise their operations.


Type Purpose DifferentiationPaper Pupils find out by reading an article how acid rain continues to affect the environment

despite attempts to clean up the air.Extension Resource


G3bActivity

ExtensionAcid rain eats away

The article on the Resource sheet appeared on the ENN website. Inthis activity, you are going to analyse the article to find informationabout how acid rain continues to affect the environment despiteattempts to clean up the air.

Read the article on the Resource sheet and then answer the questions.

1 Who carried out the report, and where?

2 What was the main finding of the report?

3 What two gases are the main causes of acid rain?

4 How successful has the 1990 Clean Air Act been in reducingemissions of these gases?

5 The article says that the area studied ‘... is actually losing its abilityto buffer acid rain’. What do you think the word ‘buffer’ means?

6 What has happened to nitrate levels in the region’s lakes?

7 How do you think these nitrates have entered the lakes?

8 What two main effects is acid rain having on the ecosystemsstudied?

9 How might this affect the region’s economy?

10 How might nitrogen oxide emissions be reduced?



G3bActivityResourceAcid rain eats away

Acid rain eats away at Northeast

By Environmental News Network StaffAcid rain continues to plague the northeastern United States, and legislation enacted in 1990 hasdone little to remedy the situation, according to a recent report by the federal General AccountingOffice.

“This report provides fresh and credible evidence that acid rain continues to damage ecosystems inVermont and throughout the Northeast,” said Sen. Patrick Leahy (D-Vermont).

“If we do not act soon to aggressively crack down on acid rain, the region’s economy and publichealth will be endangered beyond repair. We need to update our Clean Air laws with comprehensivenational legislation that forces antiquated power plants to either modernize or shut down,” saidLeahy.

Leahy and Rep. John Sweeney (R-New York) asked the GAO – Congress’ nonpartisan watchdogagency – to analyze acid rain trends in the Northeast to determine whether the 1990 update to thelandmark Clean Air Act successfully curbed sulfur dioxide and nitrogen oxide emissions.

When released into the atmosphere, these chemical compounds constitute two of the primary causesof acid rain. The GAO report found that progress had been made in reducing sulfur dioxideemissions, but emissions from nitrogen oxides remain essentially unchanged.

“Acid rain is having a tremendously damaging effect on the Northeast, and this report details justhow dire the situation really is,” said Sweeney. “The Adirondack Park is dying faster than the EPApredicted and is actually losing its ability to buffer acid rain. EPA’s worst-case scenario now appears tobe the likely outcome.”

Acid rain pollutes watersheds, creating highly acidified and nitrate-laden lakes where fish are unableto survive. Acidified soil is stripped of necessary nutrients that help plants survive cold temperatures.

A recent environmental conference at the University of Vermont revealed how vulnerable the state’ssyrup-producing maple trees are to acid rain. And Leahy cited another recent report detailing thedeclining air quality of America’s national parks as evidence of acid rain’s destructive effect.

Total sulfur dioxide emissions declined 17 percent from 1990 through 1998, but total emissions ofnitrogen oxides changed little during the same time period, according to the GAO report, “Acid Rain:Emissions Trends and Effects in the Eastern United States.” In the eastern states, total deposition ofsulfur decreased 26 percent from 1989 through 1998, while total deposition of nitrogen increased 2 percent, according to the report.

Nitrates also increased in 48 percent of the lakes sampled in the Adirondacks, a sensitive ecosystemthat is protected under the Clean Air Act.

Leahy believes the GAO report will provide the impetus for more stringent national regulation of allnitrogen oxide sources. He also hopes GAO’s findings will provide momentum for his “Clean PowerPlant and Modernization Act of 1999,” legislation introduced last year that would force 1950s-erapower plants to modernize their operations.

Article published April 3, 2000 and reproduced by kind permission of the Environmental News Network



G3cTeacher

activity notesJob hunting

Running the activityPupils read about five people whose jobs are involved in some way with the acid rainproblem, then write a letter to one of the people, introducing themselves and askingquestions about their chosen career.

Other relevant materialThe activity might fit in with the school’s careers programme. Pupils could visit thecareers library.

ICT opportunitiesPupils could search the Internet for information about other jobs associated with theacid rain problem.

Answers1 It is expected that pupils will choose Alan Locke because his project brief is

directly related to acid rain.

2 Letters should ask sensible questions about the nature and conditions of thework, qualifications required, opportunities for career development and evenremuneration.


Type Purpose DifferentiationPaper Pupils engage in a letter-writing activity based on an environmental topic to develop

literacy skills and raise awareness of science-related careers.Core


G3cActivity

CoreJob hunting


In this activity, you are going to find out how people in different careers areinvolved with the acid rain problem.

Read the following fact files.

Imagine you are considering a career that could have an impact on the acid rainproblem. Your careers adviser has suggested you contact someone working in this area tofind out more about what they do.

1 Which of the people shown in the fact files would be the best person to contact?Explain your answer.

2 Write a letter introducing yourself to the person you have chosen. Ask questions thatwill help you decide whether you want to take up a similar career.

FACT FILEAlan Locke:BiologistAge 47Qualification BSc

Project brief: Sample fish in aScottish lake and findout the optimum pHfor their survival.

FACT FILEMohammed Afzal:BarristerAge 38Qualification LLB

Project brief: Write contracts andother legal documentsfor a chemicalmanufacturingcompany.

FACT FILESarah Jones:Soil Scientist Age 30Qualification HNDApplied Chemistry

Project brief: Analyse soil samples formineral content andmake recommendationsto a vegetable grower.

FACT FILEKirsten Forbes:Civil EngineerAge 26Qualification BEng

Project brief: Design a chimney for apower station that will betall enough to disperse allwaste gases outside theradius of the town.

FACT FILEJaspreet Kaur:Technician in a geology laboratoryAge 19Qualification GNVQ Intermediate Science

Project brief: Input data on bedrock composition for Canadian lakesand prepare a report for a copper mining company.


G4aTeacher

activity notesSlowing global warming

Running the activityThe pupils should be divided into groups, then given 5 minutes to discuss theconsequences of unfettered global warming (Resource sheet). Each group selectsa spokesperson to say a few words in the first of the class discussions.

Each group should then make a list of ways in which the amount of carbondioxide in the atmosphere could be decreased. Look at the carbon cycle theycreated in Starter G1. Ideas are written on a piece of A4 paper. A differentspokesperson is selected to speak for the group. During the second classdiscussion the ideas should be grouped according to the approach they suggest(e.g. ‘grow more plants’), by attaching them to a notice board with drawingpins, or to a wall with Blu-Tack, or to a whiteboard with magnets.

At the end of the discussion, run through the main ideas. Pupils could thenwrite a summary in their books.

Other relevant materialG4a Resource sheet

PitfallsPupils should write their ideas with marker pen and in big letters on the A4paper, so that they can be read when they are displayed. Alternatively, acetatesheets and non-permanent markers may be used to make OHT ‘slides’.

ICT opportunitiesActivity G4b gives pupils an opportunity to carry out an Internet search forinformation about global warming.


Type Purpose DifferentiationPaper Discussion

Pupils use the Resource sheet as a prompt to consider the consequences of globalwarming and the measures we could take to reduce the amount of carbon dioxide in theatmosphere.

CoreResource


G4aActivity

CoreSlowing global warming

You are going to discuss global warming and suggest ways ofreducing the amount of carbon dioxide in the atmosphere.

Carbon dioxide is a greenhouse gas. This means that increasingthe amount of carbon dioxide in the atmosphere will lead to anincrease in the average temperature of the Earth. This is globalwarming.

1 Look at the Resource sheet. It shows what may happen if thetemperature of the Earth increases.

2 Discuss in your group why it is important to slow down orstop global warming.

3 Decide who will speak for your group in the class discussion.Discuss what your spokesperson is going to say.

After the first class discussion:

4 Look at the carbon cycle you created at the start of the lesson. It shows how carbon dioxide is put into theatmosphere and taken out of the atmosphere. Discuss theseideas in your group.

5 Come up with ideas of how we could decrease the amount ofcarbon dioxide in the atmosphere. Write each idea on aseparate piece of A4 paper. Write large and clearly, so thewords can be read from a distance.

6 Select a new spokesperson to speak in the next part of theclass discussion. Your spokesperson will share your ideas withthe rest of the class.



G4aActivityResourceSlowing global warming

If the average temperature of the Earth increases ...


... ice will melt, the volume of water will increase and sea levels will rise ...

... weather patterns will change ...

... catastrophes will happen and many people will die.


G4bTeacher

activity notesResearch on global warming

Running the activityPupils carry out an Internet search to find information about the greenhouse effectand global warming. They use this information to answer a series of questions.

Other relevant materialPupils may also be provided with books or use the library to find further informationabout global warming.

Some useful websites are suggested below.

United States Environmental Protection Agency – global warming sectionCool Kids for a Cool ClimateInternational Carbon Bank & Exchange – Carbon for kids sectionAbelard – global warming, a briefing document, sectionGlobal WarmingGlobal Warming: Early Warning SignsThe UK National Air Quality Information ArchiveBBC – Climate Change section

PitfallsSome pupils will find the Internet search difficult to carry out.

AnswersPupils should provide data to support the ideas of global warming and use this towrite a report. They should also quote differing opinions about global warming andpresent their own views.


Type Purpose DifferentiationICT Pupils use the Internet to find more information about global warming. Core










G4bActivity

CoreResearch on global warming

You will use the Internet to find more information about the greenhouse effect and global warming, and use thisinformation to present an argument for or against action to reduce global warming.

Obtaining evidence

1 Carry out an Internet search for information about thegreenhouse effect and global warming.Concentrate on the following areas:

� possible causes of an increase in the greenhouse effectduring the past century

� data to support or deny the idea of global warming� the possible effect of global warming on local climates� other possible harmful effects of global warming� ways that global warming may be reduced� opinions about global warming expressed by different

scientists� the attitude of politicians towards the need to reduce global

warming and the action this would require


2 Present the data you get from the Internet in a way thatsupports or rejects the idea that an increase in the greenhouseeffect is responsible for global warming.Use tables, charts and graphs to make your data clear and easyto follow.


3 Using the evidence you have put into tables, charts andgraphs, write a short report stating how the evidence shows,or does not show, that the greenhouse effect is increasing andthat this is causing global warming.

4 Quote the opinions of scientists and politicians on theexistence of global warming and the measures that are neededto avoid catastrophe.

5 Give your own views on global warming and what action, if any, you think should be taken to reduce it.



G5aTeacher

activity notesWeather forecast

Running the activityPupils study weather forecasts on video and from newspapers. They work ingroups to decide what information is recorded by meteorologists and how thisis used. Each group reports their ideas to the class for general discussion.

Pupils may watch a TV weather forecast and/or cut out a newspaper weatherforecast as homework. A video of a recent TV weather forecast should berecorded to be shown to the class. Photocopies of a recent newspaper weatherforecast should be made for use in class.

PitfallsPupils cannot be relied upon to bring material into class. Sufficient must beavailable.

ICT opportunitiesPupils could search the Internet for weather forecasts. There are a number ofsuitable sites, e.g. the weather section of the BBC website.

AnswersExpect the class discussion to include ideas about storage of data concerningrainfall, temperature, air pressure, wind speed, wind direction. Pupils may alsosuggest that this data needs to be available over a wider area than the UK topredict future weather patterns. Uses of this information may include everydayactivities of the public, sports fixtures, outdoor events, e.g. concerts, buildingprojects, insurance companies.


Type Purpose DifferentiationDiscussion Pupils find out what data is recorded by meteorologists and how this information

is used.Core



G5aActivity

CoreWeather forecast

You are going to study weather forecasts to find whatinformation is recorded by meteorologists and what use we make of this information.

Equipment

� printed copies of newspaper weather forecasts� video of a TV weather forecast.


1 Watch the video of a weather forecast. As you are watchingthink about the information that has been collected in order tomake the forecast.

2 Look at the weather forecast that appeared in a newspaper.Again think about the information that has been collected inorder to make the forecast.

3 Discuss with the other members of your group whatinformation meteorologists collect. Make a list.

4 Discuss with other members of your group what use we makeof this information. Do different people use the information indifferent ways? Make a note of your ideas.

5 Your group will be asked to present ideas to the class fordiscussion. Choose a spokesperson from your group to do this.



G5bTeacher

activity notesEvidence for global warming

Running the activityPupils use the Resource sheet, containing data about climate change over thepast 1000 years. They work individually or in groups to answer the questions.Ideas can then be shared with the class for discussion.

Evidence obtained from the NOAA (National Environmental Satellite, Dataand Information Service) Satellites and Information website.

Other relevant materialG5b Resource sheet

PitfallsSome pupils will need help in interpreting the data on the Resource sheet.

ICT opportunitiesPupils could search the Internet for further data to support the theory of globalwarming.

Answers1 yes

2 Average global temperatures have been increasingly above normal duringthe past approximately 80 years.

3 Approximately 1920 to 2000.

4 During these years fuels obtained from crude oil have been burned inincreasing quantities.

5 This burning of fossil fuel has released increasing amounts of carbondioxide into the atmosphere. Carbon dioxide is a greenhouse gas.

6 There have been small variations up and down.

7 There has been a large increase in temperature.

8 The more recent increase is far greater than the ‘normal’ variations thathave occurred over the past 1000 years.

9 This evidence neither supports nor opposes their views. Evidence frommuch further into the past is needed.


Type Purpose DifferentiationPaper Pupils study some data about changes in climate over the past 1000 years in order to

decide whether this shows evidence of global warming.CoreResource




G5bActivity

CoreEvidence for global warming

You are going to study some data about changes in climateover the past 1000 years in order to decide whether thisshows evidence of global warming.

Look at the Resource sheet: Global temperature anomalies. Thisshows how far the mean temperature of the Earth has risen orfallen from ‘normal’ in the years from 1880 to 2001.

1 Does this evidence support the idea of global warming?

2 Explain your answer to Question 1.

3 During which years has the average temperature of the Earthbeen hotter than normal?

4 What major change in our use of energy resources occurredduring these years?

5 How might this change in use of energy resources have causedthe increase in average global temperature?

Look at the Resource sheet: Paleoclimatic data. This shows detailsof the temperature in the northern hemisphere of the Earth for thepast 1000 years. This information has been gained by studyingsuch things as the rate of growth of trees.

6 How has the temperature of the northern hemisphere variedduring the whole 1000 years?

7 Describe how changes in the past 100 years compare withchanges in the previous 900 years.

8 What evidence does this provide for the idea of globalwarming?

9 Some scientists say that the recent rise in global temperature isa natural event that occurs occasionally over a very long time,perhaps many thousands of years. Does this evidence supportor oppose their views?



G5bActivityResourceEvidence for global warming

Global temperature anomalies

This graph shows how annual global mean temperature has risenor fallen from ‘normal’ in the period from 1880 to 2001.

The zero line represents the long-term mean temperature from1880 to 2001, and the bars above and below this zero line showannual increases or decreases from the mean.

Paleoclimatic data

Paleoclimatic data is data on weather conditions going back for athousand years or more. Many natural events are affected byclimate changes, such as the growth rate of a tree for example.These provide natural ‘archives’ of climate information. This dataenables us to extend our knowledge of climate variation beyondwhat is measured by modern instruments.


Land and Ocean0.90.60.30.0

–0.3–0.60.60.30.0

–0.3–0.61.2

0.6

0.0

–0.6

–1.21880 1900

Year1920 1940 1960 1980 2000

Annual global mean temperature anomalies

Ocean

Land

Annualincrease ordecrease frommeantemperature(°C)

Instrumental data (AD 1902 to 1999)Reconstruction (40 year smoothed)

1998 instrumental value

Annualincrease ordecrease frommeantemperature(°C)

1.0

0.5

0.0

–0.5

–1.01000 1200 1400 1600

Year1800 2000

Instrumental and reconstructed annual temperaturedata for northern hemisphere AD 1000 to 2000



G1 PlenariesEnvironmental chemistry

Review learning� Pupils work in groups to match words to definitions.

� Each group reports matches to the class for discussion.

� Write the correct matches on the board.

Sharing responses� Pupils work in groups to prepare a short report of their results from Activity G1a.

� Each group in turn presents their results to the class.

� Ask pupils to give their answers to the questions on the Activity G1aworksheet.

� Discuss the answers, explaining why any wrong answers that are given areincorrect.

Group feedback� Pupils work in groups to answer the question ‘How does different soil affect

the plants that grow in it?’

� Groups report their ideas to the whole class for discussion.

� Elicit ideas of different plants preferring to grow in different pH conditions,but even acid-tolerant plants have a limit to the pH of soil in which they willgrow.

� Also mention that plants may live but not grow well if soil pH is not suitable.This may reduce the yield of crops grown by farmers.

Brainstorming� Pupils work in groups to brainstorm the question ‘How can soil pH be

changed?’


� Ask pupils why it might be a good idea to change the pH of soil.

� Elicit ideas of improvement of crop yields to lead to discussion aboutneutralisation of soil acidity, and the use of lime.

Looking ahead� Pupils work in groups to suggest what effect a soil with low pH may have on

the crops and trees that grow in it.


� Lead a discussion on to ideas of crop yield and ‘farming’ of trees for paper,furniture, house construction.

� You might mention the death of many trees in Scandinavia that it isclaimed has resulted from acid rain caused by power station fumes blown fromthe UK.

➔ Pupil sheet


Review learning

Pupils work in groups tomatch words todefinitions.

Sharing responses

Each group prepares ashort presentation of theirresults from Activity G1a.

Group feedback

In groups, pupils useinformation from Activity G1bto answer the question ‘Howdoes different soil affect theplants that grow in it?’

Brainstorming

In groups, pupils brainstorm thequestion ‘How can soil pH bechanged?’

Looking ahead

In groups, pupils suggestwhat effect acid may haveon crops and trees.

G-Plenaries.qxd 11-May-04 7:40 PM Page 1

G1 PlenariesEnvironmental chemistry

Review learning

Here is a list of terms that are connected with soil pH.

acidalkaliclayhumusindicatormineralsneutralpHpollutionrock fragmentssandsoil

Match each term with its correct definition given in this list.

� small pieces of rock

� a substance that dissolves in water to form a solution with a pH above 7

� part of soil that has come from animals and plants

� sticky part of soil that has come from very fine rock fragments

� a substance that dissolves in water to form a solution with a pH below 7

� chemical substances contained in rocks

� substance that has different colours in acid and alkali

� pH 7

� comes from the weathering of granite

� a measure of how acidic or alkaline a solution is

� chemicals introduced into water, soil and air by cars, industry, etc.

� a mixture of rock fragments, including sand and clay, and humus




G2 PlenariesAcid rain

Review learning� Pupils are given a worksheet containing cards with details of the processes and

equations involved in the formation of acid rain.

� Pupils work individually or in groups to cut out and place the cards in the correctorder to form a flow chart for the formation of acid rain. Explain to pupils thatthe flow chart will need to be a branched shape.

� Pupils take turns to present their ideas.

� Write the correct sequence on the board and explain any misconceptions.

Sharing responses� Pupils work in groups to prepare a short report of their results for Activity G2a.

� Each group in turn presents their results to the class.

� Ask pupils to give their answers to the questions on the Activity G2a worksheet.

� Discuss the answers, explaining why any wrong answers that are given areincorrect.

Group feedback� Pupils work in groups to look at their results from Activity G2b and to brainstorm

the question ‘How did acidity get into this water?’

� Each group in turn presents their ideas to the class for discussion.

� Elicit ideas about local sources of pollution that may be the cause of acidity inthe rainwater samples, or lack of these if the rainwater is neutral.

Word game� Pupils use a worksheet containing cards, some of which contain statements that

are associated with acid rain and some of which contain statements that are notdirectly connected with acid rain. Pupils cut out the cards.

� Pupils work individually or in groups to sort the cards into two piles: thoseconnected with acid rain and those that have no direct connection with acid rain.

� Each pupil or group reports where they have placed one card. All cards areconsidered in turn. Any cards placed in the wrong pile are discussed in more detail.

Looking ahead� Pupils work in groups to answer the question ‘What else, other than plants, may

be affected by acid rain?’

� Each group in turn presents their ideas to the class for discussion.

� Elicit ideas about corrosion of statues and buildings, the corrosion of metals, andhealth issues such as asthma.

➔ Pupil sheet

➔ Pupil sheet

Answersnot directlyconnected withacid rain:fertilisers;hydrochloric acid;nuclear powerstations;pesticides; spaceshuttle


Review learning

Pupils arrange cardsshowing the processes andequations involved in theformation of acid rain. Theyarrange them in the correctorder to make a flow chart.

Sharing responses

Pupils work in groups toprepare a short account oftheir findings from ActivityG2a.

Group feedback

Pupils work in groups tolook at results from ActivityG2b and brainstorm thequestion ‘How did acidityget into this water?’

Word game

Pupils check their progress so farin this unit by sorting cards intotwo sets: things that are to dowith acid rain and things thatare not connected with acidrain.

Looking ahead

In groups, pupilssuggest what else,apart from plants, maybe affected by acidrain.

F

B E

AC

H

G D



Review learning

These statements describe processes involved in the formation ofacid rain.

Cut out each of the statements to make a ‘card’.

Arrange the statement cards in a flow chart to show the order inwhich the processes occur.

You will need to use a branched shape for your flow chart.


A Sulphur trioxide dissolves in rainwater to form sulphuric acid.sulphur trioxide + water → sulphuric acid

B During combustion of fossil fuels sulphur compounds burn toform sulphur dioxide.

C Some of the sulphur dioxide is oxidised by ozone to formsulphur trioxide.

D Nitrogen oxides dissolve in rainwater to form nitric acid.nitrogen dioxide + water → nitric acid

E Sulphurous acid, sulphuric acid and nitric acid cause the rainto be acidic, i.e. to have a pH below 7.

F Fossil fuels such as natural gas, central heating oil, petrol anddiesel oil are burned.

G As petrol is burned in a car engine some of the nitrogen in theair forms oxides of nitrogen.

H Sulphur dioxide dissolves in rainwater to form sulphurous acid.sulphur dioxide + water → sulphurous acid



Word game

Here are some cards. Some are about acid rain and some are not.

Cut out each card and arrange them into two piles: those connected with acid rain andthose that have no connection with acid rain.


petrolhydrochloric

acid

sulphuricacid

fossilfuels

corrosion ofstatues

nitrogenoxides

nitric acid

pesticides

power stationsburning oil, gas or

coal

space shuttle

fertilisers

sulphurousacid

nuclear powerstations

growth ofplants

sulphur dioxide

pH



G2 PlenariesInvestigate: What makesrainwater acidic?

Review learning� Ask individual pupils to present their predictions and

their conclusions to the rest of the class.

� Ask them to say how closely their predictions matchtheir conclusions.

� Lead a discussion about the information used to makepredictions and the evidence used to make conclusions,and which is more reliable.

Group feedback� Groups present their ideas about the data as a short

written report.

Analysing� Lead a class discussion based on the questions on the

worksheet and patterns observed in the data. Ask eachgroup to contribute their ideas.

Evaluating� Pupils from each group report their ideas on the validity

and reliability of the conclusions they have reached.

� Lead a class discussion on the reliability of the data andthe validity of conclusions drawn from it.

� Ask pupils to suggest what additional data could beobtained to make the conclusions more valid.


Review learning

Lead a discussion comparingpupils’ predictions with theirconclusions.

Group feedback

Groups present their ideas aboutthe data as a short written report.

Analysing

Ask a volunteer from each group toreport the patterns they have foundin their data for class discussion.

Evaluating

Groups report their ideas of validity andreliability of their conclusions for classdiscussion.



G3 PlenariesMore about acid rain

Review learning� Pupils look at slides or photos of limestone caves.� Remind pupils that even ‘normal’ rainwater is slightly acidic because carbon

dioxide from the air dissolves in it to form carbonic acid. This is ‘acidic rainwater’rather than ‘acid rain’. Carbonic acid is a very weak acid, so this rainwater is farless acidic than acid rain, which contains the strong acid sulphuric acid.

� Pupils work in groups to decide how the caves were formed.� Groups report their ideas for class discussion. Elicit ideas of the timescale

involved in cave formation (thousands/millions of years) because of the veryslow reaction of carbonic acid with calcium hydroxide.

� Contrast this with the much quicker corrosion of limestone statues andbuildings by acid rain containing sulphuric acid.

Sharing responses� Pupils work in groups to prepare a report on one of the jobs in Activity G3c.� Each group reports their ideas back to the class for discussion. List ideas for each

job on the board.� Lead the discussion on to assess how much influence the person with each of

the jobs may have on the acid rain problem.

Group feedback� Pupils work in groups to prepare a short verbal report on their results from

Activity G3a.� Each group delivers their report to the rest of the class. On the board, make

notes of the main points raised by each group.� Lead a class discussion about the effect of acid on rocks and metals.

Word game� Pupils work in groups to match problems associated with acid rain with

possible solutions to these problems. Note that there may be more than onesolution to each problem.

� Each group reports one of their matches to the class for discussion. Ask pupilsto explain how the solution will solve the problem. Lead the class discussionon to assess how well the solution would solve the problem.

� Compare different solutions to see which may be more feasible.

Looking ahead� Pupils look at a video showing hurricanes, floods, recently formed deserts, etc.� Tell pupils that many people think that extremes of weather such as strong winds,

excessive rainfall, and lack of rainfall have become more frequent in recent years.� Ask pupils to suggest a reason why these weather extremes may be more

frequent now than a hundred years ago.� Pupils may suggest global warming. If not, this idea can be introduced and

discussed.


➔ Pupil Sheet

AnswersPA solutions SB SD(note SF is a possiblebut not a goodsolution); PBsolutions SC SE (alsoperhaps SA); PCsolution SA (note SGis not a solution)



Review learning

Show slides or photos oflimestone caves. In groups,pupils decide how the caveswere formed. Catalyst InteractivePresentations 3

Sharing responses

Each group of pupilsprepares a report on one ofthe jobs in Activity G3c.Each group reports back tothe class on the impact ofthat job on acid rain.

Group feedback

Groups of pupils reportto the class on theirresults and conclusionsfrom Activity G3a.

Word game

Pupils match cards, eachwith a different problemconcerned with acid rain, toa solution for the problem,and explain why. Pupils orgroups report ideas to class.

Looking ahead

Show a video of hurricanes,floods, deserts, etc. Suggestthat these extremes of weatherseem to be increasing. Catalyst InteractivePresentations 3


G3 PlenariesMore about acid rain

Word game

These cards show some of the problems related to acid rain andpossible solutions to these problems.

1 Cut out each of the cards.

2 Try to match each problem to a solution. You may find thatmore than one solution matches a problem.

3 Think carefully how this solution will solve the problem, andmake a note of your ideas.

Problems

PA The exhaust gases of cars include oxides of nitrogen.

PB Oil burning power stations release sulphur dioxide into the air.

PC Home central heating systems using coal, oil or gas releasesulphur dioxide into the air.

Solutions

SA Encourage the installation of better insulation in homes.

SB Improve public transport.

SC Use more alternative power sources for electricity generation,e.g. wind power, wave power.

SD Fit a catalytic converter to every car.

SE Build more nuclear power stations.

SF Increase the price of petrol to discourage people from usingcars.

SG Convert more homes to use electric heating instead of coal,oil or gas.




G4 PlenariesGlobal warming

Review learning� Pupils use a worksheet to match words associated with

global warming with their definitions.

� Pupils report their answers to the whole class fordiscussion. Write correct answers on the board.

� Explain any misconceptions that become apparent fromwrong answers.

Sharing responses� Pupils in turn present their answers to the questions in

Activity G4b.

� Lead answers on to a discussion of the evidence forglobal warming.

� Encourage pupils to bring their charts, tables, etc. to thefront of the room for the rest of the class to see (it maybe possible to copy some of them onto the board ormake OHTs).

Group feedback� Pupils work in groups to compare their predictions and

observations from the ‘grow your own greenhouseeffect’ starter activity.

� Each group reports their results and explanations to theclass. Note results and key ideas on the board.

� Lead a discussion of the way that a greenhouse worksand how this relates to the greenhouse effect.

Word game� Pupils complete a crossword puzzle about pollution.

Looking back� Pupils revise and consolidate knowledge from the unit.

They can use the Unit map, Pupil checklist or the Testyourself questions.

➔ Pupil sheet

➔ Pupil sheet

AnswersAcross: 3 greenhouse; 7 pH; 8 salt; 9 methane; 12 carbon; 13 drop; Down: 1 temperature; 2 fossil; 4 rain; 5 sulphur; 6 warming; 10 pond; 11 ice

➔ Unit map

➔ Pupil checklist

➔ Test yourself


Review learning

Pupils match wordsassociated with globalwarming with theirdefinitions.

Sharing responses

Pupils present theiranswers to Activity G4b tothe class for discussion.

Group feedback

In groups, pupils compareresults and predictions for the‘grow your own greenhouseeffect’ suggested for Starter G4.

Word game

Crossword puzzle using wordsassociated with pollution.

Looking back

Pupils revise andconsolidate knowledgefrom the unit.



Review learning

This list shows terms that are to do with global warming.

Match each term with one of the definitions given below.

Terms

carbon dioxidecombustionfossil fuelgreenhouse effectgreenhouse gas

Definitions

reaction with oxygen, scientific term for burning

any gas that causes the greenhouse effect, e.g. carbon dioxide,methane

gas with the formula CO2, released when a fossil fuel is burned

trapping of energy from the Sun in the Earth’s atmosphere,caused by the presence of gases such as carbon dioxide

general term for coal, oil or natural gas




Word game

Complete this crossword puzzle about pollution.


Clues across

3 the effect that causes global warming

7 units of acidity

8 compound formed when acid rainreacts with a carbonate

9 compound in natural gas that burns toform carbon dioxide and water

12 element that forms a dioxide whenfossil fuels are burned

13 not much rain!

Clues down

1 global warming causes this to rise

2 burning these fuels causes globalwarming

4 pollution may cause this to becomeacidic

5 dioxide that causes acid rain

6 overall effect of greenhouse effect onthe Earth

10 acid rain may kill fish living here

11 global warming may cause this to meltat the North and South Poles

1 2

3 4 5

6 7 8

9

10

11

12

13



G5 PlenariesLooking at the evidence – Think about

Group feedback� Pupils work in groups to prepare a short verbal report

on their findings from Activity G5b.

� Each group in turn presents their ideas to the class fordiscussion.

� Pupils can be given the worksheet containing quotesfrom scientists, or these can be read out.

� Ask pupils to comment on these quotes. Do they agree?Why (or why not)?

Bridging to other topics� After working through the Pupil book spread G5,

remind pupils that some scientific issues arecomplicated and that data about them can be open tovarious interpretations. This means that different peoplecan argue opposite points of view from the same data.

� To show another issue where data can be open tovarious interpretations show the pupils the pupil sheetas an OHT about smoking and lung cancer and lead aclass discussion using the questions on the right. Thedata is from the Action on Smoking and Health (ASH)website.

� Tell pupils that much more evidence has now beengathered, and that most scientists believe that there issuch a link, but some scientists, mainly those workingfor tobacco companies, still deny the link.

� Ask pupils to suggest any other issues they can think ofthat seem to have inconclusive interpretations of theevidence.

➔ Teacher sheet

➔ Pupil sheet

Questions1 Does the data suggest a link between

smoking and lung cancer? If so, explainhow the data shows this link.

2 Can you think of another explanationthat would fit the data? Give details.

3 What further information is required tomake a conclusive link between smokingand lung cancer?


Group feedback

Groups of pupils present their ideas from Activity G5b for classdiscussion. The extent of disagreement between scientists as to theexistence of global warming can be emphasised by reading out quotesfrom some scientists.


Pupils describe and interpret patterns in data about smoking to discoverthat this data is open to various interpretations. A class discussionfocuses on why and how this data can be abused. Pupils suggest otherareas of science where the interpretation of data is open to question,e.g. health/food data in nutrition.




G5 PlenariesLooking at the evidence

Group feedbackTeacher sheetThe following quotes are from scientists talking about global warming.

Scientist A‘Global mean temperatures have shown a clear trend in anomalies greater thanthe long term mean temperature over the past 60 years, whereas before thatanomalies were generally lower than the long term mean temperature. Theonly interpretation that can be made from this is that the mean temperature ofthe Earth is increasing. This is powerful evidence for global warming.’

Scientist B‘Although some evidence does point to an increase in the mean temperature ofthe Earth over the past 100 years, the actual temperatures in different parts ofthe Earth vary enormously from day to day, month to month and year to year.It is impossible to make certain conclusions from data with such variation.’

Scientist C‘The study of natural phenomena has given data of global temperatures overthe past 1000 years. Such data for the northern hemisphere clearly shows adramatic temperature increase over the past 100 years. It cannot be acoincidence that this period of time has seen an equally dramatic increase inthe burning of fossil fuels. Global warming is happening now.’

Scientist D‘It is not safe to make firm conclusions using global climate data gathered fromnatural phenomena. This data has been obtained by measuring things like thethickness of tree rings, and is open to considerable error. Much firmer evidenceis needed for us to be certain that global warming is taking place.’



G5 PlenariesLooking at the evidence


The table below gives information about deaths from lung cancer.

Here are comments from two scientists about this data.

Scientist 1‘The data shows a clear link between lung cancer and thenumber of cigarettes smoked. It is obvious that smoking causeslung cancer.’

Scientist 2‘Although the data shows that there is a higher death rate fromlung cancer in those who smoke more cigarettes, this is notconclusive proof that smoking causes lung cancer. It could bethat those who smoke more cigarettes also take part in someother activity that is the true cause of lung cancer.’


Number of cigarettes Annual death rate per smoked per day 100,000 men

0 10

1–14 78 (8 times that of non-smokers)

15–25 127 (13 times that of non-smokers)

25 or more 251 (25 times that of non-smokers)


G1 SpecialsEnvironmental chemistry

1 Draw lines to match the words to the descriptions.

2 Write true or false for each sentence.

a Soils made from granite contain a lot of sand and clay.

b Soils made from limestone or chalk have a lot more sand than clay.

c Soils made from granite are alkaline.

d Soils made from limestone or chalk are alkaline.

e We use universal indicator to find out if a soil isacidic or alkaline.

3 Use these words to fill in the gaps.

a Smog is a mixture of fog, and .

b Today, air pollution in cities comes from .

c To keep our water clean, is treated before it goes intorivers.

d When a company pollutes a river, they have to pay .


chemicalweathering

environment

physicalweathering

soil

This is made up ofthe land, sea and air.

Breaking rocks intosmaller pieces.

This is made whenrocks are weathered.

Chemical reactions changingrocks into new substances.

sootcars fines sewage smoke

G-Specials.qxd 08-Jun-04 3:00 PM Page 1

G2 SpecialsAcid rain

1 Draw lines to match the words to the descriptions.

2 Look at this list of words and phrases. Use the list to help you answer the questions.

a Name three fossil fuels. , and

b Name the acid that is made when carbon dioxide dissolves in rain water.

c Name a natural source of sulphur dioxide.

d Name a man-made source of sulphur dioxide.

e sulphur + oxygen →


More acidic becauseof the sulphuric acid in it.

Slightly acidic becauseof the carbonic acid in it.

These are weathered byrain water or acid rain.

rain water

acid rain

limestone statues and buildings

coalcarbonic acid volcanic eruptions

burning fossil fuels oil sulphur dioxide gas


1 Here are some sentences about acid rain. Draw lines to match the beginnings and endings.

2 Write true or false for each sentence.

a Power stations do not release sulphur dioxide gas into the air.

b We can all help reduce pollution by changing ourlifestyle.

c Scientists monitor air and water pollution.

d Waste gases from power stations are sprayed with an acidic solution to neutralise the sulphur dioxide.

e The alkali called lime can be added to lakes to neutralise acid lake water.

3 The moreenergy you use, the morepollution ismade.

Look at this list.Draw a circleround all thethings you cando to reducepollution.

G3 SpecialsMore about acid rain


turn the lightsoff

walk to the shops catch a busto school

ride a biketo school

leave thelights on

turn downthe heating

take the carto the shops

15

1617

1918

OFF

ON

turn upthe heating

15

1617

1918

Acid rain corrodes ...

Acid rain weathers ...

Acid rain damages ...

Acid rain kills ...

... limestone, buildings, sculptures.

... fish.

... trees.

... iron bridges and metal machinery.


G4 SpecialsGlobal warming

1 Use some of these words to fill in the gaps.

gas in the air traps some of the heat fromthe Sun.

This helps to keep the Earth’s the same.

This is called the effect.

If the amount of this gas goes up, the Earth will become .

This is called .

2 Look at this list of words and phrases.

a Colour in blue the phrases that describe what car exhaust contains.

b Colour in red the phrases that describe what global warming will do.

c Colour in green the things we can do to help stop global warming.


colderbrickhouse temperaturecarbon dioxide

global warming global cooling hotter greenhouse

oxygen

poisonousgases

melt the iceat the North

and South poles

cycle or walk to school

dry up the rain so drought

will follow

sootysmoke

burn less coal,oil and gas

carbondioxide

raise the sea level and flood land

reuse orrecycle materialsto save energy

make the weather more violent

warm upthe Earth

change theenvironment


G5 SpecialsLooking at the evidence


1 Look at these two graphs. They both show the average temperature ofthe Earth and the amount of carbon dioxide in the air.

Graph A shows the data over 40 recent years. Graph B shows the data over the last 200 years. Use these graphs to help you answer the questions about them.

a Over the last 200 years the average temperature of the Earth hasgone .

b The amount of carbon dioxide in the air has gone .

c Graph gives the strongest evidence for the Earth’s’changing temperature. This is because it:

� shows information for fewer years

� shows information for more years

� shows the temperature and carbon dioxide data

� is a different graph.

380

370

360

350

340

330

320

310

300

0.4

0.3

0.2

0.1

0.0

–0.1

–0.2

1961

1971

1981

1991

Uni

ts o

f car

bon

diox

ide

Mea

n an

nual

tem

per

atur

edi

ffere

nce

in ˚

C

380

370

360

350

340

330

320

310

300

290

280

1.00.8

0.6

0.4

0.20.0

–0.2–0.4

–0.6

–0.8

–1.2

Year

Year

temperaturedifference

–1.0

1800

1820

1840

1860

1880

1900

1920

1940

1960

1980

2000

Uni

ts o

f car

bon

diox

ide

Mea

n an

nual

tem

per

atur

edi

ffere

nce

in ˚

C

Graph A

Graph B temperaturedifference

carbondioxide

carbondioxide

Tick the boxto show theright answer


G5 SpecialsLooking at the evidence (continued)

2 This table gives data about the Earth’s average temperature and theamount of carbon dioxide in the air for some years.

Year 1880 1900 1920 1940 1960 1980 2000

Amount of 290 296 302 310 321 340 370carbondioxide

Average 13.7 13.9 13.8 13.9 14.0 14.2 14.3temperature of the Earth in ºC

a On the grid below, draw a line graph to show the amount ofcarbon dioxide in the air in these years.


Am

ount

of c

arbo

n di

oxid

e

Year

1880 1920 2000

290

280

300

340

370


G5 SpecialsLooking at the evidence (continued)

b On the grid below, draw a line graph to show the averagetemperature of the Earth from 1880 to 2000.

c What is the pattern in the amount of carbon dioxide between theyears 1880 and 2000?

d What is the pattern in temperature between the years 1880 and2000?


Tem

per

atur

e in

°C

Year

1880

13.6

13.5

14.0

13.9

14.3

14.5


G Specials answersEnvironmental chemistry

G1 Environmental chemistry1 physical weathering – Breaking rocks into

smaller pieces.soil – This is made when rocks areweathered.chemical weathering – Chemical reactionschanging rocks into new substances.environment – This is made up of the land, sea and air.

2 a true c false e trueb false d true

3 a soot, smoke c sewageb cars d fines

G2 Acid rain1 rainwater – Slightly acidic because of the

carbonic acid in it.acid rain – More acidic because of the sulphuric acid in it.limestone, statues, buildings – These areweathered by rainwater or acid rain.

2 a coal, oil, gasb carbonic acidc volcanic eruptionsd burning fossil fuelse sulphur dioxide

G3 More about acid rain1 Acid rain corrodes … iron bridges and metal

machinery.Acid rain weathers … limestone, buildings,sculptures.Acid rain damages … trees.Acid rain kills … fish.

2 a false b true c true d false e true3 Circled – Turn lights off. Turn down the heating.

Walk to the shops. Ride a bike to school.

G4 Global warming1 carbon dioxide, temperature, greenhouse,

warmer, global warming2 a Coloured blue – Poisonous gases. Sooty

smoke. Carbon dioxide.b Coloured red – Ice at the North and South

Poles will melt. Rain will dry up and drought

will follow. Sea level will rise and land will be flooded. Weather will get more violent.The Earth will warm up. The environmentwill change.

c Coloured green – Cycle or walk to school.Burn less coal, oil and gas. Reuse or recyclematerials to save energy.

G5 Looking at the evidence1 a up

b upc B, shows information for more years

2 a

b

c It is going up.d It is going up.

Tem

per

atur

e in

°C

Year

1880 1900 1920 1940 1960 1980 2000

13.6

13.5

13.7

13.8

14.1

14.2

14.4

14.0

13.9

14.3

14.5

Am

ount

of c

arbo

n di

oxid

e

Year

1880 1900 19401920 2000

290

280

300

310

340

370

320

330

350

360

1960 1980


Spe Answers.qxd 6/23/2004 9:19 AM Page 7

G1 HomeworkEnvironmental chemistry


HELP

1 Look at the drawing of Andy and Clare at the seaside.

a Say which part of the environment the following things are polluting.

i the factory ii the dog iii the people

Choose from: water air land

b i What is causing the pollution from the factory?

ii What is the other main source of this kind of pollution now?

c i Which gas, in the air, do animals need to survive?

ii Which gas do plants need to photosynthesise?

iii Which of the main gases in the air is not used directly by animals or plants?

CORE

2 Look again at the picture shown for question 1.

a i Explain how the material flowing through the sewage pipe is likelyto be different today, compared with 50 years ago.

ii Why have these differences been important to the wildlife in rivers?

iii Using information from the picture, explain why the swimmer shouldstill not assume that the water is free from pollution.

iv Some beaches now achieve the ‘Blue Flag’ standard. This means thatthey must have unpolluted water and sand. Suggest ways that the beachshown could make sure it reaches the Blue Flag standard.

G-Homework.qxd 08-Jun-04 2:42 PM Page 1

G1 HomeworkEnvironmental chemistry (continued)

EXTENSION

3 a i What type of weathering is taking place at the base of the cliffsshown in the picture?

ii Describe how this type of weathering affects the base of the cliff.

b i What type of weathering takes place when rain falls onto the cliffsand streams down them?

ii Explain how and why this type of weathering affects the rocks in the cliff.

c Which type of weathering is more likely to have formed the beach sand?

d The cliffs in the picture are made from granite. What would be themain difference between plants that grow well on soil from these cliffsand plants that grow well on soil from limestone cliffs?



G2 HomeworkAcid rain

HELP

1 Match the beginning of each sentence with the correct ending.Write out each complete sentence. One ending does not fit anyof the beginnings.

2 Which of the following might produce acid rain?

A Burning gas in a power station.

B Burning magnesium ribbon in a Science lab.

C A burning pine forest.

D An erupting volcano.

E Burning sulphur in a sulphuric acid factory.


Beginnings Endings

A The sulphur in volcanoes 1 contains carbonic acid.

B Naturally acidic rainwater 2 because the rock reacts with sulphuricacid.

C Fossil fuels give off sulphur 3 goes into the air as sulphur dioxide.dioxide when they burn

D Limestone statues are chemically 4 because limestone is soluble in water.weathered by acid rain

5 because they contain sulphur whichreacts with oxygen from the air.

+


G2 HomeworkAcid rain (continued)

CORE

3 a Write a word equation to represent what happens whencarbon dioxide forms naturally acidic rainwater.

b Write another word equation to represent what happenswhen sulphur burns to form sulphur dioxide.

c i Only about half of all acid rain comes from naturalprocesses such as volcanoes and forest fires. Where doesthe rest come from?

ii What can you say about the solubility of sulphur dioxidein water?

iii Sulphur dioxide does not contain enough oxygen to turndirectly into sulphuric acid in acid rain. Suggest where theextra oxygen needed comes from.

d Suggest one way that petrol companies can help to reduceacid rain pollution from cars.

e i Why does acid rain have a lower pH value than normalrainwater?

ii Suggest a possible value for the pH of acid rain.

EXTENSION

4 a It has become common, in some large cities, to wear amedical face mask when walking to work. Explain whether ornot doing so will help to avoid the effects of air pollution.

b Explain why limestone buildings at the corners of busy road junctions tend to be more weathered than those in the country.

c Complete the following symbol equation to represent theformation of naturally acidic rainwater.

CO2 + H2CO3

d Write a symbol equation to represent the reaction thathappens when sulphur (S) burns in air to produce sulphurdioxide (SO2).



G3 HomeworkMore about acid rain

HELP

1 a Read each of the statements below, then write down whethereach one is true or false.

A Acid rain damages machinery because it is corrosive.

B Most acid rain is caused by people smoking.

C Power stations clean up waste gases by spraying them with a weak acid, to neutralise the sulphur dioxide.

D Britain’s acid rain does not fall in Britain because the windcarries it to Norway.

E Turning off lights at school makes no difference at all to acidrain pollution.

b Copy and complete the sentences below.

i Lime is added to acidic lakes because .

ii Limestone is a natural form of .

iii A salt is formed when acid rain is .



G3 HomeworkMore about acid rain (continued)

CORE

2 Copy and complete each of the statements below.

a Scientists monitor air and water pollution because .

b Many limestone buildings have been weakened because .

c Buildings made from granite are less damaged than limestone ones

because .

d Walking to school reduces air pollution because .

e Acid rain has affected many forests in Europe because .

3 Limestone can be added to lakes to remove the acidity.

a Use the chemical names below to write a word equation to represent the effect oflimestone on acid lake water.

b Calcium hydroxide solution can be used to remove the sulphur dioxide frompower station chimneys. Explain why it works.

c Explain why using very tall chimneys is not really the answer to acid rainproblems.

EXTENSION

4 a Give three ways in which acid rain damages plants.

b The formulae of five substances are given below. Use them to write a symbolequation that represents the reaction between acid rain and limestone.

c Explain how catalytic converters help to reduce atmospheric pollution.

d Why would a pH meter be useful to a water quality scientist?


calcium sulphate

calcium carbonate

water sulphuric acid

carbon dioxide

CaSO4CO2

H2O CaCO3 H2SO4


G4 HomeworkGlobal warming

HELP

1 Look at the drawing of a greenhouse. The letters show where information labels should be.

a The missing information labels are shown below. Write down the label letter and then the number of the label that should link to it.

b i Which gas, in the atmosphere, acts like the glass in the greenhouse?

ii What do we call the warming effect caused by this gas?

iii Write down one reason why this gas has increased over the last 200 years.

iv Write down two things that could happen if the amount of this gas in the air keeps on rising.


A

B

D

C

1 Some of the heat energy escapes into space.

4 The soil gives out some thermal energy into the air in the greenhouse.

3 The glass traps some of the thermal energy inside the greenhouse.

2 Energy from the Sun heats up the soil.


G4 HomeworkGlobal warming (continued)

CORE

2 Look at the ‘equation’ below.

Energy gained by the Earth – Energy lost into space = Earth’s energy balance.

Use this ‘equation’ to answer the following questions.

a i Explain how the Earth can maintain a steady temperature.

ii What will happen to the temperature if the energy loss decreases?

iii What will happen to the temperature if the energy gain increases?

b Explain why there is unlikely to be much change in the energy gained in the foreseeable future.

c Explain why an increase in the burning of fossil fuels would affect the Earth’s energy balance.

d Explain why increasing the use of cars could lead to flooding.

EXTENSION

3 Look at the table of data about carbon dioxide production.


Country Population CO2 produced per person per year in tonnes

UK 60 million 9.5

USA 280 million 19.5

India 1000 million 1.1

a Calculate the total amount of carbon dioxide produced by each country per year.

b Suggest reasons why the USA has such a large CO2 output compared with India, despite its relatively smaller population.

c Much of both India and the USA are vast rural areas with little industry. Where does the majority of the CO2 pollution come from?

d Major international companies are now building very large factories in countries such as India. Suggest a reason why they are doing this.

e What is likely to happen to the CO2 output of developing countries over the next 20 years?


G1Homework

mark schemeEnvironmental chemistry


HELPQuestion Answer Mark

1 a i Air 1

ii Land/water 1

iii Land/water 1

b i The smoke/burning fuels. 1

ii Cars 1

c i Oxygen 1

ii Carbon dioxide 1

iii Nitrogen 1

Total for Help 8

COREQuestion Answer Mark

2 a i 50 years ago – raw sewage; full of bacteria. 3Today – treated so no raw sewage; treated waste water only; bacteria free. Accept any sensible response containing three comparative points.

ii Water less polluted 1so plants and animals are not killed by pollution now. 1

iii Dog mess will probably get into the water. 1

iv Constantly test the water for pollutants. 1Use good purification processes in the sewage works. 1Sweep the beach clean every day. 1Ban dogs from the beach. 1Accept other sensible suggestions.

Total for Core 10

EXTENSIONQuestion Answer Mark

3 a i Physical weathering. 1

ii Waves beat/smash/bash/pound against the cliff 1breaking it up into smaller pieces of rock. 1Response must give clear idea of physical force being applied.

b i Chemical weathering. 1

ii Water reacts with the rock 1to form new substances, which dissolve in the water. 1

c Physical weathering. 1

d Plants on granite soils are acid-loving but plants on limestone soils are alkali-loving. 1

Total for Extension 8


G2Homework

mark schemeAcid rain



1 Correct pairings are: A – 3; B – 1; C – 5; D – 2. 4

2 A, C, D and E. 4

Total for Help 8


3 a carbon dioxide + water carbonic acid 2Award 1 mark for reactants and 1 mark for the product.

b sulphur + oxygen sulphur dioxide 2Award 1 mark for reactants and 1 mark for the product.

c i From human processes/from burning/from factories/from cars. 1ii It must be soluble in water. 1iii From the air. 1

d Remove the sulphur from the fuel before it is burned. 1

e i Sulphuric acid is a strong acid. 1ii Accept answer in range pH 1–4. 1

Total for Core 10


4 a Either:Yes because the mask will stop small carbon particles from being breathed in.or:No because the pollutants are gases that can get through the material of the mask. 1Mark for the reason rather than the yes or no response.

b Busy road junctions have stationary vehicles giving off lots of sulphur dioxide into the air 1and this will cause chemical weathering of the buildings. 1There are fewer stationary vehicles in the country 1so less sulphur dioxide is given off. 1

c Missing formula is:H2O 1

d S + O2 SO2 2Award 1 mark for correct formula of both reactants and 1 markfor correct formula of the product.



G3Homework

mark schemeMore about acid rain



1 a A – true 1B – false 1C – false 1D – true 1E – false 1

b i Lime is added to acidic lakes because it neutralises the acid/it is a base/itreacts with the acid forming a salt. 1

ii Limestone is a natural form of calcium carbonate. 1

iii A salt is formed when acid rain is neutralised/reacted with an alkali (or base). 1Underscore is pupil response. Accept alternative related responses.

Total for Help 8


2 a It helps them to work out how to deal with the pollution problem. 1

b They have been weathered very quickly by acid rain. 1

c Granite is not attacked by acid rain. 1

d Burning fuel in a car produces sulphur dioxide. 1

e It kills trees. 1Accept appropriate alternative responses for all five statements.

3 a calcium carbonate + sulphuric acid calcium sulphate + carbon dioxide + water 2Deduct 1 mark for each misplaced substance, to a maximum of 2.

b Calcium hydroxide is a base 1so it neutralises the acidic sulphur dioxide. 1

c The polluting gases just get blown somewhere else. 1

Total for Core 10


4 a Damages leaves preventing photosynthesis. 1Damages bark, letting disease/insects into the tree. 1Removes/washes out nutrients from the soil/releases poisonousaluminium that damages roots. 1

b CaCO3 + H2SO4 CaSO4 + CO2 + H2O 2

c They convert poisonous carbon monoxide/nitrogen oxides into lessharmful substances, such as CO2/N2. 2Award 1 mark for the general idea and 1 mark for naming a specific pollutant.

d To measure how acidic the water is. Accept appropriate alternative responses. 1



G4Homework

mark schemeGlobal warming



1 a A – 2; B – 4; C – 1; D – 3. 33 or 4 correct = 3 marks; 2 correct = 2 marks; 1 correct = 1 mark

b i Carbon dioxide 1

ii The greenhouse effect. 1

iii More fossil fuels being burned/more cars using petrol/forests arebeing cut down/populations are increasing. 1Accept one sensible suggestion.

iv Any two from:Air temperature rises/Polar ice caps melt/Sea levels rise/Floodingaround the coasts/Unpredictable weather/More rain/More drought/etc. 2Accept other sensible suggestions.

Total for Help 8


2 a i The difference between energy gain and loss keeps the energy level the same; 1so the temperature stays the same. 1

ii It will rise. 1

iii It will rise. 1

b The Sun is in a steady state/gives a constant supply of energy. 1Accept other equivalent responses.

c Burning fossil fuels produces carbon dioxide. 1Increasing carbon dioxide reduces the energy lost into space 1so the energy remaining increases, raising the temperature. 1

d Cars generate carbon dioxide, which increases global warming 1and flooding is a possible consequence of global warming. 1

Total for Core 10


3 a UK – 570 million tonnes; USA – 5460 million tonnes;India – 1100 million tonnes. 3

b Two from:The USA is much more technologically advanced.Americans expect a higher standard of living, which uses more energy.There are more cars in the USA. 2Accept equivalent responses.

c From the cities/from industrial sites. 1

d It/land/employment is much cheaper/pollution regulations are less strict. 1

e It will rise. 1



G Test yourselfEnvironmental chemistry

1 Choose from these pH values to answer the questions below.

a What is the pH of neutral water?

b A good growing soil is very slightly acidic. What is its pH?

c What may be the pH of an alkaline limestone soil?

d Which could be the pH value of naturally acidic rainwater?

2 Rearrange the letters to make the name we give to naturally occurring water that contains pollutants such as sulphur dioxide.

RADII CAN

3 Look at the list of gases. Underline two which cause air pollution.

argon hydrogen oxygen

carbon dioxide nitrogen sulphur dioxide

4 Underline two gases in this list that cause acid rain:

argon nitrogen oxygen

hydrogen nitrogen oxide sulphur dioxide

methane

5 Rearrange these letters to make the word we use to describe what scientists are doing when they keep measuring pollution levels.

IN MOTOR

6 Complete the following word equations.

carbon + oxygen →

sulphur + oxygen →

acid + carbonate → + +

acid + metal → +

7 For each of these statements about acid rain, write true or false.

a Gases responsible for acid rain are produced in car engines.

b Sulphur dioxide is released every time a volcano erupts.


pH 2 pH 4 pH 6 pH 7 pH 8

Test-Qust.qxd 6/25/2004 10:32 AM Page 20

G Test yourselfEnvironmental chemistry (continued)

c There are no natural sources of the sulphur dioxide in the atmosphere.

d Sulphur dioxide is removed from waste gases by treatment with an acid.

e Sulphur dioxide from power stations is the major source of sulphur dioxide in the atmosphere.

f In lakes, problems caused by acid rain are solved by adding a metal.

g Acid rain has a pH between 2 and 5.

h Acid rain can cause damage to rocks, metals and living things.

i Nitrogen oxides cause acid rain.

j Catalytic converters can’t reduce acid rain.

8 Here is a list of statements about the greenhouse effect. They are in the wrong order. Write the letters to show the correct order of the statements. The first letter has been written for you.

A The increased greenhouse effect is making the Earth warmer.

B This is called the greenhouse effect.

C Energy from the Sun heats up the Earth.

D The Earth gives out energy as heat.

E Heat energy is reflected back by greenhouse gases in the atmosphere.

The correct order is: C

9 Complete the following sentences. Use the words below to fill the gaps. You may use each word once, more than once, or not at all.

a Global warming could cause the sea temperatures to .

b The rising temperature will cause the icecaps to .

c More water in the oceans will cause the sea level to and

will result in .

d The climate will change so that farmers might have to grow different

or people may .


starve crops fall flooding melt rise

Test-Qust.qxd 6/25/2004 10:32 AM Page 21

GTest yourself

AnswersEnvironmental chemistry

1 Choose from these pH values to answer the questions below.

a What is the pH of neutral water?

b A good growing soil is very slightly acidic. What is its pH?

c What may be the pH of an alkaline limestone soil?

d Which could be the pH value of naturally acidic rainwater?

2 Rearrange the letters to make the name we give to naturally occurring water that contains pollutants such as sulphur dioxide.

RADII CAN

3 Look at the list of gases. Underline two which cause air pollution.

argon hydrogen oxygen

carbon dioxide nitrogen sulphur dioxide

4 Underline two gases in this list that cause acid rain:

argon nitrogen oxygen

hydrogen nitrogen oxide sulphur dioxide

methane

5 Rearrange these letters to make the word we use to describe what scientists are doing when they keep measuring pollution levels.

IN MOTOR

6 Complete the following word equations.

carbon + oxygen →

sulphur + oxygen →

acid + carbonate → + +

acid + metal → +

7 For each of these statements about acid rain, write true or false.

a Gases responsible for acid rain are produced in car engines.

b Sulphur dioxide is released every time a volcano erupts. true

true

hydrogensalt

watercarbon

salt

dioxidesulphur

dioxidecarbon

MONITOR

ACID RAIN

pH 6

pH 8

pH 6

pH 7

dioxide


pH 2 pH 4 pH 6 pH 7 pH 8

Test-Ans.qxd 16-Jun-04 2:55 PM Page 20

GTest yourself

AnswersEnvironmental chemistry (continued)

c There are no natural sources of the sulphur dioxide in the atmosphere.

d Sulphur dioxide is removed from waste gases by treatment with an acid.

e Sulphur dioxide from power stations is the major source of sulphur dioxide in the atmosphere.

f In lakes, problems caused by acid rain are solved by adding a metal.

g Acid rain has a pH between 2 and 5.

h Acid rain can cause damage to rocks, metals and living things.

i Nitrogen oxides cause acid rain.

j Catalytic converters can’t reduce acid rain.

8 Here is a list of statements about the greenhouse effect. They are in the wrong order. Write the letters to show the correct order of the statements. The first letter has been written for you.

A The increased greenhouse effect is making the Earth warmer.

B This is called the greenhouse effect.

C Energy from the Sun heats up the Earth.

D The Earth gives out energy as heat.

E Heat energy is reflected back by greenhouse gases in the atmosphere.

The correct order is: C

9 Complete the following sentences. Use the words below to fill the gaps. You may use each word once, more than once, or not at all.

a Global warming could cause the sea temperatures to .

b The rising temperature will cause the icecaps to .

c More water in the oceans will cause the sea level to and

will result in .

d The climate will change so that farmers might have to grow different

or people may .starvecrops

flooding

rise

melt

rise

ABED

false

true

true

true

false

true

false

false


starve crops fall flooding melt rise

Test-Ans.qxd 16-Jun-04 2:55 PM Page 21

GEnd of unit test

GreenEnvironmental chemistry

1 Rocks are broken down by weathering.

Write the letter for each type of weathering alongside the letter for the correct example. 2 marks

2 a Why are higher levels of pollutants found in the city than in the country when pollutants are monitored? 1 mark

b Give one way in which we can reduce pollutants being released into the air. 1 mark

3 a Acid rain is caused by certain gases in the atmosphere. Which two gases below cause acid rain? 2 marks

b Which of the following fuels produces the most gases that lead to acid rain? 1 mark

c Name one of the acids contained in acid rain. 1 mark

d What do you need to do before you can take steps to control pollution? 1 mark

4 Most people think that the Earth is warming up, a process called global warming. Energy reaches the Earth from the Sun.

a Why does the Earth not get too hot? 1 mark

b Some of the energy from the Sun is trapped by a gas in the atmosphere.

i Name this gas.ii What is the name given to the effect of trapping energy

in the atmosphere? 1 mark

c The amount of carbon dioxide in the atmosphere has increased in the last 200 years. What is the most likely reason for this increase? 1 mark

d There have been very warm and also very cold periods before in the Earth’s history.

i Why is the current warming different from any previous ones? 1 markii Give three changes in the environment that could happen as

a result of global warming. 3 marks


Type of weathering Example

A biological weathering X changes in temperature break up rocks

B chemical weathering Y roots of trees and shrubs grow through rocks

C physical weathering Z acids in rainwater break down rocks

oxygen nitrogen nitrogen oxide sulphur oxide

coal hydrogen natural gas smokeless fuel

G-I-EUTest.qxd 18-Jun-04 10:47 AM Page 1

GEnd of unit test

GreenEnvironmental chemistry (continued)

5 Acid rain can affect rocks and metals. Copy and complete these word equations to show what is produced. 3 marks

a zinc + → zinc sulphate + hydrogen

b calcium carbonate + sulphuric acid → calcium sulphate +

+

6 In December 1952 the Great London Smog caused many people to die. Smog is a mixture of smoke and fog. Most homes had coal fires, and power stations were built in city centers.

In 1956, the Government introduced the Clean Air Act to reduce smoke pollution from homes by introducing smokeless zones. In these areas, only smokeless fuels could be burnt.

The graph shows the amount of sulphur oxide, in millions of tonnes, emitted in theUnited Kingdom, from 1971 to 1997.

a In what year was sulphur dioxide emission at its highest? 1 mark

b i What is the pattern in sulphur dioxide emission from 1971 to 1997? 1 mark

ii In which year did sulphur dioxide emission reach about half what it was in 1971? 1 mark

The Clean Air Act was meant to reduce smoke pollution, but the use of cleaner coals and electricity and gas, rather than coal, for cooking and heating also helped to reduce sulphur dioxide levels at the same time. Also, power stations were moved to more rural areas.

c i What does the evidence suggest was the main source of sulphur dioxide pollution? 1 mark

ii What would you predict the effect would be on sulphur dioxide levels in towns when power stations were moved to rural areas? 1 mark


7.00

6.00

5.00

4.00

3.00

2.00

1.00

0.00

Sulp

hur

diox

ide

(mill

ion

tonn

es)

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997


GEnd of unit test

RedEnvironmental chemistry

1 Most people think that the Earth is warming up, a process called global warming.Energy reaches the Earth from the Sun.

a Why does the Earth not get too hot? 1 mark

b Some of the energy from the Sun is trapped by a gas in the atmosphere.

i Name this gas. 1 markii What is the name given to the effect of trapping energy in the

atmosphere? 1 mark

c The amount of carbon dioxide in the atmosphere has increased in the last 200 years. What is the most likely reason for this increase? 1 mark

d There have been very warm and also very cold periods before in the Earth’s history.

i Why is the current warming different from any previous ones? 1 markii Give two changes in the environment that could happen as

a result of global warming. 3 marks

2 Acid rain can affect rocks and metals. Copy and complete these word equations to show what is produced. 3 marks

a zinc + → zinc sulphate + hydrogen

b calcium carbonate + sulphuric acid → calcium sulphate +

+

3 The atmosphere in cities is monitored constantly.

a Why are pollutants such as nitrogen oxides monitored? 1 mark

b Carbon dioxide, ozone, sulphur dioxide and nitrogen oxides are four pollutants that are monitored. Name another substance that is monitored. 1 mark

c The levels of pollutants can be affected by weather conditions. Suggest why. 1 mark

d Nitrogen dioxide is formed in car engines when nitrogen and oxygen combine. Write a word equation for this reaction. 1 mark

e Ozone, O3, is a reactive form of oxygen formed when nitrogen dioxide reacts with oxygen. The other product is nitrogen monoxide. Write a balanced symbol equation for this reaction. 2 marks

f Nitrogen dioxide reacts with oxygen and water to form nitric acid, HNO3. Explain what happens when nitric acid reacts with a carbonate such as calcium carbonate. 3 marks

g Name one gas that scientists think might contribute to global warming. 1 mark



GEnd of unit test

RedEnvironmental chemistry (continued)

4 In December 1952 the Great London Smog caused many people to die. Smog is a mixture of smoke and fog. Most homes had coal fires, and power stations were built in city centres.

In 1956, the Government introduced the Clean Air Act to reduce smoke pollution from homes by introducing smokeless zones. In these areas, only smokeless fuels could be burnt. But the introduction of cleaner coals and the increased use of electricity and gas, rather than coal, for cooking and heating also helped to reduce sulphur dioxide levels at the same time. Also, power stations were moved to more rural areas.

a i What does the evidence suggest was the main source of sulphur dioxide pollution? 1 mark

ii What would you predict the effect would be on sulphur dioxide levels in towns when power stations were moved to rural areas? 1 mark

This graph shows sulphur dioxide emission from 1962 to 1997.

b What does this graph tell you about sulphur dioxide emissions in 1971 compared with 1962? 1 mark

c i What would be your prediction for sulphur dioxide emission in 2006? Explain how you were able to make your prediction. 1 mark

ii Why is it important to take measurements like this over as long a time as possible? 1 mark


180

160

140

120

100

80

40

20

0

60

1962

1964

1966

1968

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

Year beginning April

Con

cent

ratio

n (µ

g m

–3)


GEnd of unit test



Green (NC Tier 3–6)Question Answer Mark Level

1 AY, BZ, CX 1 3(One or two correct: one mark; three correct: two marks) 1 4

2 a There are more cars and factories in cities producing pollutants. 1 4

b Any one form: 1 4Use less fuel.Use less energy.Walk or cycle instead of using the car.Insulate homes better.(accept other suitable answers)

3 a Nitrogen oxide. 1 4Sulphur dioxide. 1 4

b Coal 1 3

c Sulphuric acid or nitric acid. 1 5

d Monitor levels of pollutants so you know what the pollutants are. 1 4

4 a Much heat is lost, or reradiated, back into space. 1 6

b i Carbon dioxide. 1 5ii Greenhouse effect. 1 5

c Burning of fossil fuels. 1 5

d i Caused by human activity. 1 6ii Three from: Ice caps may melt causing sea levels to rise; some land 3 5

may be flooded by the sea; weather will become more violent; some areas may get hotter and dry up; failed crops may cause famine.

5 a Zinc + sulphuric acid → zinc sulphate + hydrogen (One mark for sulphuric acid.) 1 6

b Calcium carbonate + sulphuric acid →calcium sulphate + carbon dioxide + water 2 6(One mark for carbon dioxide, one mark for water.)

6 a 1971 and/or 1973 1 4

b i It is going down, slowly at first and then more rapidly. 1 5ii 1993 1 5

c i Coal/fossil fuels. 1 6ii Levels would go down. 1 6

Scores in the range of: NC Level

4–6 3

7–11 4

12–16 5

17–25 6


GEnd of unit test



Red (NC Tier 5–7*)Question Answer Mark Level

1 a Much heat is lost, or reradiated, back into space. 1 6

b i Carbon dioxide. 1 5ii Greenhouse effect. 1 5

c Burning of fossil fuels. 1 5

d i Caused by human activity. 1 6ii Two from: 2 5

Ice caps may melt causing sea levels to rise; some land may be flooded by the sea; weather will become more violent; some areas may get hotter and dry up; failed crops may cause famine.

2 a Zinc + sulphuric acid → zinc sulphate + hydrogen (One mark for sulphuric acid.) 1 6

b Calcium carbonate + sulphuric acid →calcium sulphate + carbon dioxide + water (One mark for carbon dioxide, one mark for water.) 2 6

3 a So scientists know the levels of pollutants in different places or 1 6because pollutants are harmful to people and the environment.

b Any one from: 1 6Carbon monoxideMethaneor any other pollutant gas.

c Any one from: 1 7Soluble pollutants dissolve in rainwater.The wind blows pollutants to different areas.

d Nitrogen + water → nitrogen dioxide 1 6

e NO2 + O2 → O3 + NO (One mark for reactants, one mark for products.) 2 7*

f The acid reacts with calcium carbonate to produce carbon dioxide,water and calcium nitrate. 3 7

g Carbon dioxide or methane. 1 7

4 a i Coal/fossil fuels. 1 6ii Levels would go down. 1 6

b Emission in 1971 was half what it was in 1962. 1 6

c i It could be half that in 1996. By extending the pattern of the graph. 1 7ii To be able to see clear trends across a period of time so that your

conclusions are reliable. 1 7

Scores in the range of: NC Level

6–10 5

11–15 6

16–18 7

19–25 7*


G Pupil checklistEnvironmental chemistry


Learning outcomes I can do I can do I need to this very this quite do more well well work on this

I understand how the air, water and soil can be polluted.

I can describe how soil is formed.

I can carry out a soil test for acidity.

I can name which plants grow well in different soils.

I can describe how acid rain is formed.

I can identify the sources of acid rain.

I can carry out an experiment to find the effect of acid rain on plants.

I can use secondary data to investigate the causes of acidity in rainwater.

I can describe some of the problems caused by acid rain.

I understand that air and water pollution are monitored to help find solutions.

I can describe the jobs of some scientists dealing with the problems of acid rain.

I can describe the greenhouse effect.

I can describe the causes and effects of global warming.

I can use information to assess how global warming has taken place over a period of time.

Pupil-Checklist.qxd 17-Jun-04 8:00 PM Page 7

G GlossaryEnvironmental chemistry


Word

acid rain

anomaly

catalytic converter R

global warming

monitor

pollution

Definition

The contamination of water, air or soil by harmful or toxicsubstances.

Rain polluted by acidic gases such as sulphur dioxidedissolved in it. Acid rain is more acidic than rainwater that isnot polluted.

To check and measure over a period of time.

A device fitted to a car’s exhaust that removes some of thepolluting gases by chemical reactions. R

An increase in the average temperature of the Earth.

Something that is more than, less than or different to what is normal or expected.

Glossary.qxd 18-Jun-04 11:33 AM Page 8

G Key wordsEnvironmental chemistry

acid rain

anomaly


global warming

monitor

pollution

acid rain

anomaly


global warming

monitor

pollution

Sheet 1 of 1

Sheet 1 of 1

© Harcourt Education Ltd 2004 Catalyst 3This worksheet may have been altered from the original on the CD-ROM.

Key wordsG Environmental chemistry

© Harcourt Education Ltd 2004 Catalyst 3This worksheet may have been altered from the original on the CD-ROM.

Keywords.qxd 18-Jun-04 11:35 AM Page 7


G Book answersEnvironmental chemistry

G1 Environmental chemistryGreena acidicb The soil in Cornwall was acidic. The London soil

was alkaline.c Gas or oil.1 Plants can’t grow in rocks because ... they can’t

get the nutrients they need from rock until it isweathered.Rocks form soil when they are broken down and... the chemicals in them react with air and water.Heather grows well in Scotland because ... soil isacidic.

2 Open coal fires are not allowed in London today.3 Sewage is treated before being put into rivers.

Companies are fined if they discharge pollutedwater into rivers.

Reda i Heathers and azaleas.

ii Clematis and camellias.b The soil in Cornwall was acidic. The London soil

was alkaline.1 No. Soil produced by the weathering of granite

is naturally slightly acidic.2 There are so many cars in London that the

pollution is still a problem.3 Scientists monitor the pollution levels. Fish have

returned to the Thames. People swim in it.4 The Clean Air Act cured the air pollution

problem in London. The air pollution increasedin other parts of the country where coal wasused to produce the smokeless fuel thatLondoners can use.

G2 Acid rainGreena Acid rain causes damage to buildings and statues

made of limestone.b Red pH paper shows that the water is acidic.c Coal, gas and oil.d Max is right. There’s not a lot we can do about

natural forms of pollution. But we should try tostop the pollution we do cause.

1 Normal rain is slightly acidic because ofdissolved carbon dioxide. Acid rain is moreacidic because of dissolved sulphur dioxide.

2 a Either of: volcanoes, forest fires.b Burning fossil fuels.

3 If there is less sulphur in the petrol, then lesssulphur dioxide is put into the air when thepetrol is burned.

Reda Acid rain causes damage to buildings and statues

made of limestone.

b Max is right. There’s not a lot we can do aboutnatural forms of pollution. But we should try tostop the pollution we do cause.

1 a Factories burned fossil fuels which put a lotof sulphur dioxide into the air.

b The cars on the motorway put sulphurdioxide into the air from burning petrolcontaining sulphur. The sulphur dioxidecaused acid rain which damaged the trees.

2 a One from: burning of fossil fuels, burning ofpetrol, respiration of animals.

b Either of nitrogen oxide, nitrogen dioxide.3 She is unlikely to be correct. The name of the

island indicates that there are or were volcanoeson the island. Volcanoes are sources of sulphurdioxide. However, she could be correct if thevolcanoes have not been active for hundreds ofyears.

4 a petrol + oxygen → carbon dioxide + waterb The reaction between nitrogen and oxygen.c They make the water acidic.

G3 More about acid rainGreena calcium carbonate + sulphuric acid → calcium

sulphate + carbon dioxide + waterb Any reasonable answer, e.g. wood, steel, marble,

granite, etc.c The sulphur dioxide from our power stations

was blown over to Norway and caused acid rainto fall there.

d Scientists invented a way to spray the waste gasesfrom power stations with alkaline solution. Thisneutralised the sulphur dioxide and cleaned thegases before releasing them into the atmosphere.

1 An alkaline solution ... is used to removesulphur dioxide from power station waste gases.Lime ... neutralises the acid in lakes.Limestone ... is badly weathered by acid rain.Acid rain . ... kills fish in rivers and lakes.

2 Individual answers.

Reda Fine details have larger surface areas than flat

surfaces. Larger surface areas make the reactionsgo faster.

b There were no instances of the sulphur dioxidelevel reaching or exceeding 100 parts per billionover the year. Therefore there was no pollutionproblem in Bexley.

1 calcium carbonate + sulphuric acid →calcium sulphate + carbon dioxide + water

2 calcium hydroxide + sulphuric acid →calcium sulphate + water

3 The limestone reacts with the acid rain when it fallsinto the lakes. This neutralises the sulphuric acid.

Book Answers.qxd 18-Jun-04 12:44 PM Page 18


G Book answersEnvironmental chemistry (continued)

4 Individual answers.5 Individual answers.

G4 Global warmingGreena Either of: power plants burning fossil fuels,

animal respiration.b Petra is correct. Although the carbon dioxide

produced and used naturally is in balance, theman made carbon dioxide builds up and causespollution.

c People living in the developing world are morelikely to suffer the effects of global warming.They have no technological resources to combatthe effects of global warming.

d Individual answers.1 Carbon dioxide ... is produced when fossil fuels

burn.The greenhouse effect ... is caused by carbondioxide in the air trapping some of the heatenergy radiated by the Earth.Flooding and droughts ... could occur if globalwarming starts to melt the ice at the poles, orchange weather patterns.Global warming ... happens if extra carbondioxide in the air increases the greenhouseeffect.

2 a If you drive your car less then less petrol isburned and less carbon dioxide is put intothe air.

b Yes, it will help to reduce the air pollution inAthens.

3 If there was too little carbon dioxide in the air,then the reverse of global warming might occur.The Earth could become colder due to loss ofenergy. Plant life is dependent on carbondioxide, so if there was too little, plants woulddie.

Reda 0.027%b If there was too little carbon dioxide in the air,

then the reverse of global warming might occur.The Earth could become colder due to loss ofenergy. Plant life is dependent on carbondioxide, so if there was too little, plants woulddie.

c People living in the developing world are morelikely to suffer the effects of global warming.They have no technological resources to combatthe effects of global warming.

d Reducing Britain’s output of carbon dioxide by6% would reduce it from 9.5 tonnes per personper year to 8.9 tonnes per person per year. Thisis a difference of 0.6 tonnes. The total global

output of carbon dioxide is 30.1 tonnes perperson per year. So Britain’s reduction would make a difference of 0.2% which is quiteinsignificant. Britain will have to reduce itscontribution of carbon dioxide by far more than6% to have a significant effect on the globaloutput.

1 a If you drive your car less then less petrol isburned and less carbon dioxide is put intothe air.

b Yes, it will help to reduce the air pollution inAthens.

c Encourage the development and use ofengines other those which use petrol such aselectric engines and hydrogen poweredengines. Also, use public transportationinstead of cars, make car engines smaller andless consumptive of fuel.

2 a There are likely to be fewer fish, as theywould not be able to adapt to thetemperature change so quickly and manywould die.

b A farmer will have a more difficult timebecause there would be less rainfall. Farmingmight be impossible if the fields have floodedfrom rising sea levels.

c Coastal hotels could be devastated by therising sea.

3 If ocean currents were to change and divert theGulf Stream away from Britain, the temperaturescould become very cold with long periods offreezing weather. In summer it would be coldand difficult to farm. Icebergs might even formin the seas.

G5 Looking at the evidenceGreena Yes. The rise in the curve showing the

temperature is roughly similar to the rise in thecurve showing the amounts of carbon dioxide inthe atmosphere.

b upwardsc An anomaly.d No. There has been a steady increase in the level

of carbon dioxide over the last 200 years.1 a Over the last 200 years, the average

temperature of the Earth has risen byjust under 2 °C

b The amount of carbon dioxide in the airhas also gone up because we have burnedfossil fuels.

c This suggests that the two are linked, butdoes not prove that burning fossil fuelscauses global warming.



G Book answersEnvironmental chemistry (continued)

2 a

b Both curves show an upward trend, risingmore quickly with passing time. The rate ofrise of carbon dioxide is greater in recentyears than the mean temperature difference.

Reda Volcanoes erupting or meteor hitting the Earth

causing the atmosphere to be polluted withgases and particles, etc.

b The temperature seems to have dipped lower fora while.

c No, there might have been some other factorcausing the temperature rise.

d There appears to be a direct link between them.e The fact that we have been burning fossil fuels

for that same length of time.f No. Temperatures were higher in the Middle

Ages and lower in the Elizabethan Age.g There have been regular and high fluctuations

of temperature and carbon dioxide levels overthe past 400 thousand years. Ice ages occurred atabout 350, 260, 170, 50 and 20 thousand yearsago.

h The temperature level change appears to haveoccurred before the carbon dioxide change. Thisdoes not support the idea that carbon dioxide iscontrolling the temperature change.

i The dramatic change is caused by the beginningof our burning of fossil fuels. It is not easy topredict what will happen next.

1 a

b The graphs show an increase in both carbondioxide levels and mean temperaturedifference. Both graphs rise much morerapidly in recent years than in earlier years.

c The graph shows an increase in mean averagetemperature difference with increasing levelsof carbon dioxide. The amounts of carbondioxide caused a much more pronouncedeffect on raising temperature differenceswhen the levels of carbon dioxide were small. At higher levels of carbon dioxideconcentrations, the effect on temperaturedifference flattens out to become almostlinear.

2 Individual answers.

Mea

n av

erag

e te

mp

erat

ure

diffe

renc

e in

°C

1820

1840

1800

1860

1880

1900

1940

1920

1980

1960

2000

–1.0

–0.8

–0.6

–0.4

–0.2

0

0.2

0.4

0.6

0.8

210

230

250

270

310

330

350

370

290

390

Year

Uni

ts o

f car

bon

diox

ide

x x x x x x xx

x

x

x

Mea

n av

erag

e te

mp

erat

ure

diffe

renc

e in

°C

1880

1900

1920

1940

1960

1980

2000

–0.5

–0.4

–0.3

–0.2

–0.1

0.1

0.2

0.3

0.4

0.5

0

0.6

270

280

290

300

320

330

340

350

360

310

370

Year

Uni

ts o

f car

bon

diox

ide

x xx

xx

x

x

Mea

n av

erag

e te

mp

erat

ure

diffe

renc

e in

°C

–1.0280 300 320 340 360 380

–0.8

–0.6

–0.4

–0.2

0

0.2

0.4

0.6

0.8

Units of carbon dioxide


G Environmental chemistry Unit guide - Physicslocker · G Environmental chemistry Unit guide Where this unit fits in Prior learning ... Risk assessments are required for any hazardous

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