Elements of ChemistryElements of ChemistryChapter 2Chapter 2

2.1 Matter Has Physical andChemical Properties

2.1 Matter Has Physical andChemical Properties

“Physical properties” describe the look or feel of a substance.

“Physical properties” describe the look or feel of a substance.

During a“physical change”

a substance changes some physical property…

During a“physical change”

a substance changes some physical property…

…but it is still the same material with the same chemical composition.

…but it is still the same material with the same chemical composition.

Chemical Property:Chemical Property:

The tendency of a substance to change

into another substance.

The tendency of a substance to change

into another substance.

OxygenOxygen CarbonCarbon

CarbondioxideCarbondioxide

CarbondioxideCarbondioxideOxygenOxygen CarbonCarbon

AnimationAnimation

“CO2Flask.mov”“CO2Flask.mov”

Chemical Change:Chemical Change:

Any change involving a rearrangement of

atoms.

Any change involving a rearrangement of

atoms.

Chemical Reaction:Chemical Reaction:

The process of a chemical change...The process of a

chemical change...

During a“chemical reaction”new materials are

formed by a change in the way atoms are bonded together.

During a“chemical reaction”new materials are

formed by a change in the way atoms are bonded together.

PhysicalChangePhysicalChange

ChemicalChange

ChemicalChange

2.2 Atoms Are the Fundamental

Components of Elements

2.2 Atoms Are the Fundamental

Components of Elements

Element:Element:

Any material consisting of only one type of

atom.

Any material consisting of only one type of

atom.

The Periodic TableThe Periodic Table

Atomic Symbol:Atomic Symbol:

One or two letters used to designate an

element.

One or two letters used to designate an

element.

Carbon, CCarbon, C

Calcium, CaCalcium, Ca

Silver, AgSilver, Ag

(Argentum)(Argentum)

(Hydrargyrum)(Hydrargyrum)

Mercury, HgMercury, Hg

Elemental Formula:Elemental Formula:

Used to show how atoms within an

element are grouped

Used to show how atoms within an

element are grouped

NN 22

22Oxygen, OOxygen, O

33Ozone, OOzone, O

OxygenOxygen OzoneOzone

OxygenOxygen OzoneOzone

Physical or chemical change?Physical or chemical change?

2.3 Elements Can Combine to Form Compounds

2.3 Elements Can Combine to Form Compounds

CompoundCompound

A material in which atoms of different

elements are bonded to one another.

A material in which atoms of different

elements are bonded to one another.

Sodium chlorideSodium chloride

Sodium chlorideSodium chloride

NaNa

Sodium chlorideSodium chloride

ClCl

AmmoniaAmmonia

AmmoniaAmmonia

NN

AmmoniaAmmonia

HH

A compound is represented by its…

A compound is represented by its…

chemical formula chemical formula

The combination of atomic symbols of the

elements of a compound

The combination of atomic symbols of the

elements of a compound

Ammonia Ammonia

Ammonia, Ammonia, NH NH 3 3

Sodium chloride Sodium chloride

Sodium chloride, NaCl Sodium chloride, NaCl

Iron oxide Iron oxide Fe Fe 2 2 O O

3 3

Compound Compound ChemicalFormula ChemicalFormula

Iron oxide Iron oxide

Sulfuric acid Sulfuric acid

Fe Fe

SO SO

2 2 O O 3 3

H H

2 2 4 4

Compound Compound ChemicalFormula ChemicalFormula

Iron oxide Iron oxide

Calcium chloride Calcium chloride

Sulfuric acid Sulfuric acid

Fe Fe

SO SO

Cl Cl

2 2 O O 3 3

H H Ca Ca 2 2

2 2 4 4

Compound Compound ChemicalFormula ChemicalFormula

Compounds have properties that are

uniquely different from the elements from which

they are made.

Compounds have properties that are

uniquely different from the elements from which

they are made.

Iron oxide Iron oxide

Calcium chloride Calcium chloride

Sulfuric acid Sulfuric acid

Fe Fe

SO SO

Cl Cl

2 2 O O 3 3

H H Ca Ca 2 2

2 2 4 4

Compound Compound ChemicalFormula ChemicalFormula

Iron oxide Iron oxide

Calcium chloride Calcium chloride

Sulfuric acid Sulfuric acid

Fe Fe

SO SO

Cl Cl

2 2 O O 3 3

H H Ca Ca 2 2

2 2 4 4

Compound Compound ChemicalFormula ChemicalFormula

Iron oxide Iron oxide

Calcium chloride Calcium chloride

Sulfuric acid Sulfuric acid

Fe Fe

SO SO

Cl Cl

2 2 O O 3 3

H H Ca Ca 2 2

2 2 4 4

Compound Compound ChemicalFormula ChemicalFormula

Sodium chloride Sodium chloride Cl Cl Na Na

Compound Compound ChemicalFormula ChemicalFormula

Sodium metal, NaSodium metal, Na

Chlorine gas, ClChlorine gas, Cl22

ReactionReaction

Sodium chloride, NaClSodium chloride, NaCl

Sodium chloride, NaClSodium chloride, NaCl

Diversity!Diversity!

From so few elements…From so few elements…

The Periodic TableThe Periodic Table

Naming Compounds Naming Compounds

Guideline 1Guideline 1

Start with the element farthest to the left in the periodic table…

Start with the element farthest to the left in the periodic table…

Guideline 1Guideline 1

…for the element farthest to the right, add the suffix -ide

…for the element farthest to the right, add the suffix -ide

ExampleExample

NaClNaCl

The Periodic TableThe Periodic Table

ExampleExample

NaClNaCl

SodiumSodium ineineChlorChlor

ExampleExample

NaClNaCl

SodiumSodium ideideChlorChlor

ExampleExample

NaClNaCl

sodiumsodium chloridechloride

Guideline 2Guideline 2

With different possible combinations of

elements…

With different possible combinations of

elements…

Guideline 2Guideline 2

…use prefixes to remove any ambiguity.

…use prefixes to remove any ambiguity.

mono-mono-di-di-tri-tri-

tetra-tetra-

2233

44

11

ExampleExample

COCO

COCO

22

carbon monoxidecarbon monoxide

carbon dioxidecarbon dioxide

ExampleExample

H OH O

H OH O

22

dihydrogen monoxidedihydrogen monoxide

dihydrogen dioxidedihydrogen dioxide

22

22

ExampleExample

H OH O

H OH O

22

dihydrogen monoxidedihydrogen monoxide

dihydrogen dioxidedihydrogen dioxide

22

22Would you drin

k this?

?

Would you drink th

is??

H OH O

H OH O

22

dihydrogen monoxidedihydrogen monoxide

dihydrogen dioxidedihydrogen dioxide

22

22

(water)(water)

(hydrogen peroxide)(hydrogen peroxide)

Guideline 3Guideline 3

Common names are also sometimes used

for convenience.

Common names are also sometimes used

for convenience.

2.4 Most Materials are Mixtures

2.4 Most Materials are Mixtures

MixtureMixture

A combination of two or more substances…A combination of two or more substances…

MixtureMixture

…in which each substance retains its

properties.

…in which each substance retains its

properties.

ExamplesExamples

“salt water”“salt water”

ExamplesExamples

NaClNaCl H OH O22++

“Air”“Air”

ExamplesExamples

NN OO22++22

“white gold”“white gold”

ExamplesExamples

PdPd AuAu++

A mixture of a gasand a liquid?

The formation of a mixture is different

from the formation of a compound.

The formation of a mixture is different

from the formation of a compound.

The formation of a mixture

The formation of a mixture

The formation of a compound

The formation of a compoundChemical Change

Chemical Change

Physical Change

Physical Change

The formation of a mixture

The formation of a mixture

The formation of a mixture

The formation of a mixture

2.5 Chemists Classify Matter as Pure or Impure

2.5 Chemists Classify Matter as Pure or Impure

PurePure

Consisting of only a single element or a single compound.

Consisting of only a single element or a single compound.

PurePure

Consisting of only a single element or a single compound.

Consisting of only a single element or a single compound.“Id

eal state”

“Ideal st

ate”

ImpureImpure

“not pure”“not pure”

ImpureImpure

A mixture…A mixture…

ImpureImpure

…containing two or more elements or

compounds.

…containing two or more elements or

compounds.

ImpureImpure

…containing two or more elements or

compounds.

…containing two or more elements or

compounds.RealityReality

Impure water can be purified by…

Impure water can be purified by…

a) removing the impure water molecules.

a) removing the impure water molecules.

Impure water can be purified by…

Impure water can be purified by…

a) removing the impure water molecules.

a) removing the impure water molecules.

Impure water can be purified by…

Impure water can be purified by…

b) removing everything that is not water.

b) removing everything that is not water.

Impure water can be purified by…

Impure water can be purified by…

b) removing everything that is not water.

b) removing everything that is not water.

Impure water can be purified by…

Impure water can be purified by…

c) breaking down the water to its simplest

components.

c) breaking down the water to its simplest

components.

Impure water can be purified by…

Impure water can be purified by…

c) breaking down the water to its simplest

components.

c) breaking down the water to its simplest

components.

Impure water can be purified by…

Impure water can be purified by…

d) adding some disinfectant such as

chlorine.

d) adding some disinfectant such as

chlorine.

Impure water can be purified by…

Impure water can be purified by…

d) adding some disinfectant such as

chlorine.

d) adding some disinfectant such as

chlorine.

Impure water can be purified by…

Impure water can be purified by…

??

2.6 Elements Are Organized in the Periodic Table by Their Properties

2.6 Elements Are Organized in the Periodic Table by Their Properties

inte

rval

inte

rval

11

22

33 44 55 66 77 88 99 1010 1111 1212

1313 1414 1515 1616 1717

1818

18 Groups18 Groups

11

22

33

44

55

66

77

Seven PeriodsSeven Periods