CHEMISTRY Mrs. Adams Room 601. Today’s TO DO: 9/7/10 Introduction Agenda Book Syllabus & Expectations Notebooks Hand out Set up Journal #1 Homework.

CHEMISTRYCHEMISTRY

Mrs. AdamsMrs. Adams

Room 601Room 601

Today’s TO DO: 9/7/10Today’s TO DO: 9/7/10

Introduction Agenda Book Syllabus & Expectations Notebooks

Hand out Set up Journal #1

Homework

Notebook

My gift to you…I expect you to BRING it and USE it E-V-E-R-Y DAY!

Set Up Leave 1st 4 sheets blank for Table of Contents

Date Title Format pg #9-7 What is Chemistry? Journal 1

9-8 if same as above, leave blank Notes

Starting with 5th sheet as pg.1, number each page in lower outer corner

Journal #1 Journal #1 – What is Chemistry?

Go to pg.1 of your notebook Write title Journal #1 – What is Chemistry? Journal #1 – What is Chemistry? on

top w/date on right, 9-7-109-7-10 Write the following prompt:

a) What do you think of when you hear the word chemistry?

b) List 10 things that you think are part of chemistry.

Leave a blank line Answer

HomeworkHomework: Real Life Application of Chemistry

Find a current article showing an application of chemistry to our lives

Write a summary in your own words that includes main ideas of the article your thoughts about the article 1-2 questions you still have that were NOT answered in the article

If done on computer, email me the article as well as your summary (GREEN )

If hand written, also provide a printout of the article

DUE: Friday, Sept. 10th

Journal #2 – Journal #2 – Self ReflectionSelf Reflection

a. How do you think your friends and family would describe you?

b. What are your goals & expectations in this class?

c. What do you hope to accomplish in the next 5 years?

d. What do you hope to accomplish in the next 15 years?

Lab SafetyLab Safety

Read the Flinn Lab Safety Directions To reinforce the concepts in your assigned

section, your table will create one of the following to present to the class: Skit Poem Cartoon Song Poster or Ad

LabLab

To do a lab really well, have your report done well in advance.

In Other Words… Know WHAT you’re supposed to do BEFORE you

do it. Know WHY you’re doing something BEFORE you

do it.

LabLab

BEFORE every lab, you will address:

Background information Materials & procedures Safety concerns Hypothesis Creation of data tables

LabLab

AFTER every lab you will

OrganizeOrganize your data into charts and graphs AnalyzeAnalyze your data Accept or reject Accept or reject your hypothesis Discuss Discuss your conclusion & possible source(s) of

error

Scientific MethodScientific Method

A way to answer questions about the world based on observations and experiments.

INQUIREINQUIRE AAsk questions

OBSERVEOBSERVE Not always visual

EXPERIMENTEXPERIMENT Changing a variable to determine

UNDERSTANDUNDERSTAND

Scientific Method in Action

CHEMOTHERAPY

OIL SPILLS

FOOD INDUSTRY

COSMETIC INDUSTRY

For each:For each:1.1. Explain the general idea of Explain the general idea of

why scientific method applies why scientific method applies 2.2. Write a SPECIFIC Write a SPECIFIC

• observation or question observation or question AND AND

• hypothesis you could testhypothesis you could test

MeasurementsMeasurements

Always uncertain Instruments never flawless Some estimation always required

Example: A ruler

Numbered lines = centimeters Reliable

Smaller lines = 0.1 cm = 1 mm Reliable

Any point between each line Must be estimated Not reliable

Ex: Line above the ruler = _____ cm Written as _______________ cm

2.45

2.45  +/- 0.01

Reliability Reliability

2 ways to check numbers repeat measurement test against standard

PrecisionPrecision how close repeated measurements are to each

other AccuracyAccuracy

how close measurements are to standard or accepted value

Precision vs. AccuracyPrecision vs. Accuracy

Sample ProblemSample Problem

In 3 separate trials, Sara calculates the density of water to be 0.88g/ml 0.87g/ml 0.88g/ml

Is she preciseprecise ? Yes, all close together

Is she accurateaccurate? No, accepted value is 1 g/ml

Significant DigitsSignificant Digits

Sig Figs Sig Figs Number of digits within a value that are

considered significant with respect measurement validity

Follows Pacific-Atlantic Rule

Decimal PPRESENT - PPACIFIC

Start at far left of number (like pacific ocean is on far left of US) 

Start counting digits @ first Non Zero number

End at rightmost digit (including zeros)

Examples

34.067g ____ sig figs

0.0007458ml ____ sig figs 

0.009070g ____ sig figs    

55

44

44

Decimal AABSENT – AATLANTIC

Start @ far right of number (like the Atlantic Ocean is at far right of US)

Start counting digits @ first Non Zero number

End at leftmost digit

Examples

2030cm ____ sig figs

2007dm ____ sig figs

19,000,000,000g ____ sig figs

33

44

22

Practice Problems

0.0026701m ____ sig figs

19.0550kg ____ sig figs

3500V ____ sig figs

1,809,000L ____ sig figs

55

66

22

44

Sig Fig's in Calculations

Exact numbers or conversions do not count as sig figs Ex: Speed of light ~ 300,000,000 m/s

Can have infinite # of sig figs and must be specified Sample –

Speed of light expressed to 3 significant digits = 3.00 x 108

Multiplication & DivisionMultiplication & Division

Answer must have same # of sig figs as lowest sig figs found within problem Ex: 2.45 x 23.678 = 58.0111 = 58.0 (3) (5) (3)

Example:  Example:  Volume = length x width x heightVolume = length x width x height

1. Find the volume an object with sides 10.876m x 1.34m x 13.22m

(5 sig figs) (3) (4)

192.6661648m (10) 192.67 m3 (5) 192.7 m3 (4) 193 m3 (3)

Addition & SubtractionAddition & Subtraction

Largest uncertainty determines number of sig figs

Answer will have lowest sig figs to the right of the decimal from numbers in problem Ex: 3.21 + 5.3442 + 279.9 = 288.4542

More ExampleMore Exampless

34.50g + 3.2345g + 671.1g + 25.345g

2092 ml – 147.54 ml

= 734.7745g ~ 734.8g

= 1944.46 ml ~ 1944 ml

Practice ProblemsPractice Problems

6.15m x 4.026m = 12.7km / 3.0  = 150ml + 76.9ml + 209ml + 0.036ml =

(35.6L + 2.4L) / 4.803  = 2.542m x (16.408m - 3.88m) =

24.8 m2

4.2 km

435.936 ~ 440 ml

7.91 L

31.85 m

Journal # 3 – Sig FigsJournal # 3 – Sig Figs

What are the rules for significant figures? Be sure to include those for addition/subtraction

and multiplication/division

Scientific NotationScientific Notation

One digit to the left of the decimal # of digits to right of decimal is determined by

sig fig rules Example 19,000,000 ml

2 sig figs 1.9 x 107 ml

Example 0.0004569g 4 sig figs 4.569 x 10-4 g 

Scientific Notation PracticeScientific Notation Practice

32,700 =

1,024,000 = 0.0047100 =

0.000000003901 =

3.27 x 104  

1.024 x 106

4.7100 x 10-3

3.901 x 10-9

Knowing Equations: Knowing Equations: Density Density

Density = mass /volume D=m/v

Know formula & manipulate w/algebra OROR know graphic below

MM

DD VV

Dimensional AnalysisDimensional Analysis

Step by step conversion between units Convert 10.0µm to inches

Conversion factors  1m=1,000,000µm   1m = 39.37inches

Start with the given unit, then use you conversion factors to cancel units until to arrive at the unit you want to convert to.

10um x  1m   x  39.37inches = 0.0003937in

      1,000,000um   1m   

Practice ProblemsPractice Problems

250.0 cm to inches ? gal in 39L ? cm in 16in ? seconds in 5 days ? ft in 86cm ? cm3 in 2.3gal ? m in 3.5mi

Percent ErrorPercent Error

% Error = measured – accepted x 100

accepted Ex:

Accepted value for density of water = 1 g/ml Measured value for density of water in lab = 0.9 g/ml

% Error = (0.9 – 1)/1 * 100 = 10% Error

Journal #4 – Dimensional AnalysisJournal #4 – Dimensional Analysis

Are there REALLY 86400 seconds in a day? Show your dimensional analysis to defend your

answer.

Chapter 2Chapter 2

i

Energy

Potential to do work or produce heat 3 Main Types –

1.1. RadiantRadiant Ex: sunlight

2.2. KineticKinetic Energy of motion

Ex: Mechanical – energy of moving parts Ex: Thermal – energy from internal particle motion in matter

3.3. PotentialPotential Ex: Gravitational – falling water Ex: Electrical – opposite charges Ex: Chemical - battery

http://entergy.apogee.net/kids/templates/kidskorner/images/lhw2.jpg

Energy Units

ccalories Amount of heat needed to raise 1g of water 1oC 1 C1 Calorie in food = 1000 ccalories

JoulesJoules SI unit of energy 1 cal = 4.184 JJ

Measuring caloriesMeasuring calories CalorimeterCalorimeter

Law of ConservationLaw of Conservation

Energy is neither created nor destroyed in any process

Energy can be transformedcan be transformed from one form to another Ex: kinetic energy of bat transferred to baseball

(kinetic, sound) Ex: Chemical energy of striking match

transformed into heat and light

TemperatureTemperature

Celsius 0oC = freezing pt 100oC = boiling pt 21oC = room temp 37oC = body temp

Kelvin SI Unit of temperature oC + 273

Matter & ConservationMatter & Conservation

Has mass & volume States

Solid Liquid Gas

Changes Physical Chemical

Just like Energy,Just like Energy,Matter can be neither created nor Matter can be neither created nor

destroyeddestroyed

ElementsElements

Substances that cannot be separated into simpler substances by chemical change

Organized in Periodic Table Combine chemically to form COMPOUNDSCOMPOUNDS

MixturesMixtures

Blend of 2 or more pure substances (elements or compounds)

HeterogeneousHeterogeneous Visible differences in combined substances

Ex: chocolate chip cookies

HomogeneousHomogeneous No visible differences in substances

Ex: salt water

Separation of Homogeneous Mixtures

1.1. DistillationDistillation Tap water = homogeneous mixture

2.2. CrystallizationCrystallization Evaporation of liquids from solids

3.3. ChromatographyChromatography Separates mixtures by

Solubility size charge

Chapter 3Chapter 3

Early Models of the AtomEarly Models of the Atom

AtomsAtoms

The Greek Philosopher Democritus Proposed all matter made up of small, indivisible

particles Called these “atomos” = atoms

Today’s DefinitionToday’s Definition- smallest particles of an element that retain properties of element

DemocritusDemocritus

Because he didn’t know what held these particles together They remained rejected until the 17th century

when better technology = closer observations

1700’s

LavoisierLavoisier Law of Conservation of matter

Joseph Louis ProustJoseph Louis Proust Law of constant composition

compounds always contains same elements in same proportions by mass

John Dalton

Atomic Theory of Matter: Each element is composed of extremely small

particles called atoms All atoms of an element are identical, but differ

from those of other elements Atoms are neither created or destroyed in a

chemical reaction A compound always has the same relative

numbers of atoms.

Discovering Atomic Discovering Atomic StructureStructure

Michael Faraday

structure of atoms is related to electricity atoms contain particles that have electrical

charge.

Static ElectricityStatic Electricity

Benjamin Franklin famous electricity experiment

Conclusions from his kite & key experiment1. lightning is a static discharge from clouds

2. electricity has two kinds of charges. Positive (+) Negative(-)

Cathode Rays & ElectronsCathode Rays & Electrons

Running electricity through a partially evacuated glass tube occurs in a cathode tube. Negative end = cathode Positive end = anode

With a fluorescent lining & addition of electricity, particles are visible

J.J. ThompsonJ.J. Thompson

Deflected particles w/magnet Discovered particles were negatively

charged Named them electrons Along w/Milikin discovered their mass to be

only 1/2000 of full atomic mass …

Ernest RutherfordErnest Rutherford

Discovers alpha particles Deflects towards negative plate Charge =

Discovers beta particles Deflect towards positive plate Charge =

Discovers gamma particles Not affected by electric plates Charge =

The Nuclear AtomThe Nuclear Atom

If electrons are negative, why are atoms neutral?

Must contain positive parts equal to the negative parts.

Where are they?

The Gold Foil Experiment (figure The Gold Foil Experiment (figure 3-14)3-14)

What does this mean?

The experiment determined that most of the atoms positive charge, as well as the mass, is in the middle, called the nucleus.

Most of the particles pass through the empty space but occasionally one gets close enough to the positive nucleus to deflect

Modern Atomic TheoryModern Atomic Theory

AtomsAtoms

Smallest units of matter

Composed of protonsprotons (+) and neutronsneutrons in nucleus and electronselectrons (-) in orbitals

www.phschool.com

1 proton has the mass of about 2000 electrons

Periodic Table InformationPeriodic Table Information

Atomic NumberAtomic Number Represents # of

protons Also # of electrons in

a stable atom of an element

Discovered by Moseley

Atomic Mass Atomic Mass Sum of protons & neutrons Electron mass is small and

almost negligible

www.sparknotes.com

ElectronsElectrons

Electrons move in space around the nucleus

Rutherford visualized it as a mini solar system.

Atomic MassAtomic Mass

Measured by Atomic Mass Units (AMU)

atomic mass approximately = protons + neutrons Atomic Mass (AM) = average mass of

element’s atoms, including isotopes

Unstable AtomsUnstable Atoms

IonsIons Different # of

electrons Atoms with a charge

IsotopesIsotopes Different # of neutrons

Often radioactive Used as diagnostic tracers

www.radiation-scott.org

IonsIons

When an atom gains or loses electrons it acquires a charge Fewer electrons means positive charge More electrons means negative charge

Charge of ion = # protons - # electrons

Sample

Write the chemical symbol for the ion with 9 protons and 10 electrons

Answer F-

What is the symbol of the ion with 13 protons and 10 electrons?

Answer Al3+

7 Protons and 10 electrons? N 3-

IsotopesIsotopes

Dalton said all atoms of an element are the same.

Not quite true, ISOTOPES have a different number of neutrons

In nature, elements are almost always found as a mixture of isotopes

Identifying IsotopesIdentifying Isotopes

To identify isotopes more specifically Use the Mass Number Mass Number = (# protons) + (# neutrons)

Fundamental Subatomic Particles

Particle Location Charge (C)

Mass (g) Mass (AMU)

Proton Inside nucleus

+1.602 x 10-19 1.673 x 10-24 1

Neutron Inside nucleus

0 1.675 x 10-24 1

Electron Outside nucleus

-1.602 x 10-19 9.109 x 10 –28 0

Changes in the NucleusChanges in the Nucleus

Radioactive ElementsRadioactive Elements

Discovered by Becquerel in late 1800s Uranium

Pierre & Marie Curie Radium & Polonium

Nuclear ReactionsNuclear Reactions

Changes in nucleus Changes composition of nucleus Alpha & beta radiation comes from nucleus

Unstable nucleus radioactivity Not many elements radioactive Why not?? Seems like all those + protons would

cause a lot of repelling…..

Composition of Stable Nuclei

As the number of protons increases, it takes more and more neutrons to remain stable.

All atoms above 83 are unstable

Radioactive DecayRadioactive Decay

RULE:RULE: sums of mass numbers & atomic sums of mass numbers & atomic

numbers are same before & after numbers are same before & after reactionreaction

Types of Radioactive Decay

1.1. Alpha RadiationAlpha Radiation Stream of high energy alpha particles

Consists of 2 protons and 2 neutrons Identical to a helium-4 nucleus Symbol 4

2He2+ or 42He or 4

2 Do not cause a health risk Do not travel far

When an atom emits one of these, it is said to be undergoing radioactive decay

Which brings us to the nuclear equation, or a way to keep track of the components

Alpha DecayAlpha Decay

2.2. Beta RadiationBeta Radiation stream of high speed electrons

neutron changes into 1 proton & electron proton stays in nucleus electron is propelled out at high speed Symbol of 0

-1e- or 0-1e or 0

-1 damaging to skin

Beta Decay

3.3. Gamma radiation Gamma radiation Extremely energetic form of light

energy we cannot see Symbolized by 0

0 Does not consist of particles Able to penetrate deeply into substances

http://www.deq.idaho.gov/inl_oversight/radiation/penetration.cfm

Types of RadiationTypes of Radiation

Name Identity Charge Penetrating Ability

Alpha ()

Helium-4 nuclei

2+ Low

Beta () Electron 1- Medium

Gamma ()

High energy particle

None high

Practice ProblemsPractice Problems

Write the nuclear equation for the alpha decay of uranium 238.

Write a nuclear equation for the beta decay of sodium 24

Other Nuclear ReactionsOther Nuclear Reactions

Nuclear Fusion Atoms collide and join together releasing great

amounts of energy Like in the Sun

Nuclear Fission Splitting the nuclei of large atoms

Like in Nuclear reactors

BondingBonding

Atoms bond in order to fill their valence shell (outer energy level)

Octet RuleOctet Rule The idea that most atoms want 8 electrons

in their outer shell and will share, steal, or give away electrons in order to fill the valence shell

Exceptions are those who have less than 6 total electrons

Covalent BondingCovalent Bonding

Valence electrons (outer shell) are shared Form molecules Single, double or triple bonds are possible

www.school-for-champions.com

Electrons are lost or gained from the outer shell in order to fulfill the octet rule

Ionic BondingIonic Bonding

www.school-for-champions.com

Hydrogen BondingHydrogen Bonding

Weak bonds formed between molecules that contain polar covalent bonds

http://trc.ucdavis.edu/biosci10v/bis10v/media/ch02/bond_types.html

Bonding animation: www.biology.arizona.edu