S2 Science Elements and Compounds REVISION By contributing to investigations into familiar changes in substances to produce other substances, I can describe.

S2 ScienceElements and Compounds

REVISION

By contributing to investigations into familiar changes in substances to produce other substances, I can describe how their characteristics have changed.SCN 2-15a

NEW LEARNING

I have developed my knowledge of the PeriodicTable by considering the properties and uses of a variety of elements relativeto their positions

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Periodic Table

Today we will learn toState what elements are and where you

canfind out information about them.

We will do this byLook at the periodic table together to

learnhow to find out information about

elements. Match elements to their uses

We will have succeeded if

Periodic Table

Find this page in your planner – you will be using it a lot!

Periodic Table

• This contains all of the elements that we know of

• Elements are the simplest atoms, they are used as the building blocks for everything in life

• Elements can not be broken down into anything simpler

In pairs…..

• Use the building blocks shown here to build as many different towers as possible

What about….

• Not so easy!!

• Like lego bricks the elements in the periodic table can form many different structures

Elements and Uses

• Work in pairs

• You will be given a set of cards, with elements and what they are used for

• You have to work together to match up the element to its use

Elements

There are five elements in the list below.Underline them.

water oxygen silver

vinegar zinc salt

bread air neon

sugar brass carbon

Classifying Elements

Today we will learn toExplain why the periodic table is

arrangedthe way that it is

We will do this byLook at the periodic table together to

learnhow to find out information about

elements. Match elements to their uses

We will have succeeded if

Periodic Table

Classifying elements

• Why do we have to put things in order?

• Think of something that you know that is put into order

• A library is put into children's section and adults section. There is also fiction and non fiction.

Classifying elements

• In pairs

• Look at the element data cards. Put them into groups depending on their properties

• If they have similar properties they will be in the same group

Chemistry trumps

• In groups of four

• Give each person in the group an equal number of cards

• Play element trumps using the information given about the elements on the cards

Groups and Periods

Today we will learn toExplain the difference between a

groupand a periodWe will do this byLooking at the periodic table to seewhere they areWe will have succeeded if

Groups and periods

Groups and periods introduction

Groups

• A group of elements will react in a similar way

Brainiac video

Group 7 - Halogens

This group contains non-metals. They arevery reactive

1 2

543 6 7

8

Group 8 – Noble GasesThis group contains non-metals. They do

notreact with other elements so are useful in

theirown way. Can you think of uses?

1 2

543 6 7

8

Quick Quiz

• What is group 1 called?• How does group 1 behave?• What is group 2 called?• How does group 2 behave?• What is group 7 called?• How does group 7 behave?• What is group 8 called?• How does group 8 behave?

Periods

• A period goes across the way in the periodic table

• Elements can be divided into METALS and NON-METALS.

• Most non-metals are non-conductors of electricity.

• Carbon (in the form of graphite) is the only non-metal which conducts electricity.

Metals and Non-metals

• Draw a line on your periodic table

• Metals are on the left hand side

Elements

• Each element is represented by a symbol.

• This symbol is made up of 1 or 2 letters.

• The symbol is unique to that element.

• The first letter is always a capital

• The second letter (if it has one) is always a small letter

MgO

HeHg

C

Fe

In Pairs…

• Write down the symbols for 5 different elements

• Get your partner to find the names

• If you get confident you could time each other!

In pairs

Use the periodic table to find the symbols for the groups of elements below. Each group should spell a different cartoon character

• Tungsten, oxygen, oxygen, dysprosium

• Sulphur, cobalt, oxygen, boron, yetrium

Mixtures and Compounds

Today we will learn toDescribe what a mixture is, and how it isdifferent from a compound

We will do this byLook at a mixture and learn how to separate

it. Watch this mixture being changed into acompound and how this is different

We will have succeeded if

MixturesA mixture is formed by simply mixing together two elements without chemically joining together

Examples of mixtures:

Air

Skittles

Iron and Sulphur

• Look at the mixture of iron and sulphur

• Try separating this mixture

• What happens when you heat this up?http://www.youtube.com/watch?v=A

5H6DVe5FAI

MixturesFiltration

This is a technique used to separate insoluble solids from liquids

MixturesFiltration

Gas Tests

Today we will learn toExplain how to test for common gasesWe will do this byTest these gases and note yourobservationsWe will have succeeded if

Hydrogen

OxygenCarbon dioxide

Gas Tests

Experiments

• Add 3ml of lime water into carbon dioxide test tube. What happens?

• Put a glowing (just blown out) splint to the neck of the oxygen test tube. What happens?

• Put a lit splint to the neck of the hydrogen test tube. What happens?

Gas Observations

Oxygen

Hydrogen

Carbon dioxide

Carbon dioxide

Carbon dioxide turns limewater cloudy

Carbon dioxide turns limewater cloudy

Hydrogen

Carbon dioxide turns limewater cloudy

Hydrogen burns with a “pop”

Carbon dioxide turns limewater cloudy

Hydrogen burns with a “pop”

Oxygen

Carbon dioxide turns limewater cloudy

Hydrogen burns with a “pop”

Oxygen re-lights a glowing splint

Mixtures and Compounds

• When two substances are mixed together they can usually be separated easily (mixture).

• When two substances join together in a chemical reaction they form a compound.

• They cannot be separated easily.

• The two substances have joined together with chemical bonds.

Compounds

What is a compound?

When atoms of different elements join together in a chemical reaction they form a new substance called a compound

This is different from a mixture, where the atoms are just mixed together and not chemically joined

Naming compounds

Compounds containing two elements end with ide

e.g. lithium + chlorine = lithium chloride

Magnesium + oxygen = magnesium oxide

Which elements…

• Sodium fluoride• Lithium bromide• Calcium oxide• Aluminium chloride• Phosphorus sulphide• Caesium chloride

Naming compounds

Two exceptions: compounds containing two element AND oxygen end in ite or ate

e.g.

copper, sulphur and oxygen = copper sulphate

Sodium, sulphur and oxygen = sodium sulphite

Which elements…

• Sodium nitrate• Lithium sulphate• Calcium phosphate• Aluminium chlorate• Phosphorus sulphite• Caesium nitrite

S2 starter

1. Name the compound formed when copper and chlorine react together.

2. What elements are in copper sulphide?3. What elements are in copper

carbonate?4. What elements are in copper chloride?5. What elements are in copper chlorite?

Breaking Compounds

Today we will learn toExplain how to break compounds apart

We will do this byCarrying out an experiment to break up

copperchloride

We will have succeeded if

Breaking Compounds• If electricity is passed through a

compound it can be separated into the elements it is made from.

• The diagram below shows the apparatus used to do this.

+-

green liquid(made from green powder dissolved in water)

6v d.c power pack

carbon rod

• The electric current is switched on.

Breaking compounds

• Aim:To break up copper chloride using

electricity

• Results:

• Conclusion:

Observations

Before the experiment

After the experiment

POSITIVE carbon rod

NEGATIVE carbon rod

Breaking Compounds

• After a few minutes copper is deposited on one carbon rod and chlorine gas given off at the other.

Copper chloride copper + chlorineCompound element + element

+

-

6v d.c power pack

copperchlorine

gas