Chemistry is the study about how matter is put together, how atoms

combine to form molecules, and how the molecules combine to

make up the many kinds of matter around us.

Classification of MatterMatter – identified and organized by properties

anything that has mass and takes up space

Properties Chemical – ability to react/combine (both what it

will and won’t react with)- will change the composition

Physical – characteristics observed or measured-will not change the composition

two kinds of physical properties help describe the behavior of a substance undergoing a physical change

 1. Extensive- depends on the amount of matter

Ex: mass, length, volume

2. Intensive- does not depend on the amount of Ex: density (regardless of size, each sample of a substance has the same density) color, crystalline shape, melting point, boiling point, phase of the matter (solid, liquid, gas), and refractive index (ability of material to bend light)

Property Physical or Chemical

Intensive or Extensive

SizeDensityColorFlammableCorrosivePhase of matter

Property Physical or Chemical

Intensive or Extensive

Size P EDensity P IColor P IFlammable C N/ACorrosive C N/APhase of matter P I

State (or phase) of matter is always a physical property: Solid, liquid, gas

Phase

Energy – move

Particle spacing

Volume Shape Compressible

Solid Little CloseRigid

Definite Definite

No

Liquid

Some CloseSlide

Definite Not Definit

e

No

Gas Lot Far Not Definite

NotDefinit

e

Yes

Changes in PropertiesPhysical change - does NOT change the

composition (identity) of the substance. Same substance remains after a change has taken place *Size: pounding, bending, grinding, pulling,

or cutting does not change the chemical character of a substance.

*Change of state: melting, boiling, vaporizing *Cutting a piece of wood into smaller pieces,

tearing paper, dissolving sugar in water, hammering copper into a new shape are all examples of physical change.

Chemical change- DOES change composition. After a change has taken place a new substance appearsChanges that produce

a new kind of matter with new, different properties. Burning, digestion, fermenting all form new substances with new and different characteristics.

Sodium- a silvery, soft metal that reacts vigorously with water (Na)

Chlorine- a yellow-green gas that is highly- corrosive and poisonous (Cl)

Yet if these two elements are brought together, they combine to form a white crystalline solid. Table salt (NaCl), which neither reacts with water, nor is poisonous.

Evidence of a chemical change:1. Heat and/or light is produced

2. Production of a gas (bubbles)

3. Odor

4. Color change

5. Formation of a precipitate – a cloudy solid which appears after mixing to clear solutions

Chemical Reactions - a Chemical change has taken place: 2 or more substances have chemically bonded together to create a new substance

Law of Conservation of Mass – matter is neither created nor destroyed. This states that mass remains constant during a chemical reaction. One of the greatest scientific achievements of the 18th century by a Frenchman, Lavoisier (1743-1794)

 Mass (of reactants) = Mass (of products)Before After

Chemical Equations: Reactant + reactant product +

product (always on left) (always on

right) ~ arrow shows directions

Ex. 12 g of calcium reacts with 6 grams of fluorine gas to produce calcium fluoride. How many grams of product will be produced?

12 g Ca + 6 g F2 ____ g CaF2 (12 + 6) = (18)

Try itDuring electrolysis you can separate water into

hydrogen & oxygen. If 10.0g Hydrogen & 79.4 g Oxygen were produced, much water was there at the start?

____ g H2O 10.0 g H2 + 79.4 g O2

89.4 g H2O 10.0 g H2 + 79.4 g O2

Mixture- matter that contains two or more different materials

Phase- any region with a uniform set of properties

Ex: sour milk, watery part is one phase while fat is the second phase

Mixtures are divided into two categories1.

Heterogeneous mixture- a mixture that is composed of more than one phase

Ex: granite, sand

2. Homogeneous mixture- materials that consist of only one phase.

If you break a piece of homogeneous matter into smaller pieces, each piece will have the same properties as every other small piece

Ex: salt water, window glass, and air

Separating Mixtures (physical separation)

1. Filtration – through a porous barrier, filters solids from liquids

2. Distillation – different boiling points2 liquids: lowest boiling point vaporizes 1st

3. Crystallization – dissolved solids from a solutions

rock candy left after water evaporates 4. Chromatography – different rate of travel

through a medium identify chemicals, DNA testing, separates

pigments, research

Pure Substances- homogeneous materials that always have the same composition

*Homogeneous mixtures are not pure substances, yet the substances that comprise them are evenly dispersed throughout the mixture

1. Elements- substances composed of only one kind of atom (elements on the P.T.)

Ex: sodium ~ Na, Iron ~ Fe, Neon ~ Ne

2. Compounds- composed of more than one kind of atom (made from multiple elements on the P.T.)

Ex: water ~ H2O, table salt ~ NaCl

Compounds cannot be physically separated, they are chemically bonded

Pure Substances are divided into two categories

Matter

Mixtures

1. 2.

Homogeneous Mixture

Solutions1. 2. 3.

Colloid-1.

2.

3.

Heterogeneous Mixture Suspension

Pure Substances

Element1. 2.

Compound1.

2.

Matter

Mixtures

1. Has Mass2. Has Volume(Occupies Space)

Homogeneous Mixture

Solutions1. 2. 3.

Colloid-1.

2.

3.

Heterogeneous Mixture Suspension

Pure Substances

Element1. 2.

Compound1.

2.

MixturesVariable Composition

Can be physically separated

Homogeneous Mixture

Uniform Throughout (But Proportions can

Vary)

Solutions1. Particles are atoms,

ions, or molecules2. Won’t scatter light3. Ex. Salt Water, Steel, Air

Colloid- Don’t settle out1. Particles larger than

molecule 2. Scatters light

(Tyndall Effect)3. Ex. Smoke, Fog

Heterogeneous MixtureNot uniform ThroughoutEx. Lumpy

SuspensionSolid in LiquidEventually settle outEx. Muddy waterWood, granite, blood

Pure SubstancesDefinite Composition

HomogeneousCan’t be physically separated

Element1. Made of atoms2. Cannot be further

separated by chemical or physical means

(on periodic table Mendeleev arranged in

rows-periods Columns-

groups/families)

Compound1. Chemical combinations

of 2 or more atoms. (elements chemically bonded)

2. Cannot by separated by physical means (CaCl2, NaCl, Sugar, C6H12O6)

Matter

Mixtures

1. Has Mass2. Has Volume(Occupies Space)

Variable CompositionCan be physically separated

Homogeneous Mixture

Uniform Throughout (But Proportions can

Vary)

Solutions1. Particles are atoms,

ions, or molecules2. Won’t scatter light3. Ex. Salt Water, Steel, Air

Colloid- Don’t settle out1. Particles larger than

molecule 2. Scatters light

(Tyndall Effect)3. Ex. Smoke, Fog

Heterogeneous MixtureNot uniform ThroughoutEx. Lumpy

SuspensionSolid in LiquidEventually settle outEx. Muddy waterWood, granite, blood

Pure SubstancesDefinite Composition

HomogeneousCan’t be physically separated

Element1. Made of atoms2. Cannot be further

separated by chemical or physical means

(on periodic table Mendeleev arranged in

rows-periods Columns-

groups/families)

Compound1. Chemical combinations

of 2 or more atoms. (elements chemically bonded)

2. Cannot by separated by physical means (CaCl2, NaCl, Sugar, C6H12O6)

Law of Definite Proportions

% by Mass = Mass of element x 100

Mass of compound

If compounds have the same % by mass, they must be the same

Regardless of amount, a compound is always composed of the same elements in the same proportion by mass

80 g sample of compound contains 20 g of hydrogen. What is the percent by mass of hydrogen?

20 g x 100 = 25%80 g

If 7 g of iron combine with 3 g of oxygen, what is the % by mass of iron? Of oxygen?Hint: Find the total mass 1st

% iron = 7g x 100 = 70%

10 g

%oxygen = 3g x 100 = 30%10g

Try itSample 1 contains 15.0 g of H2 and 120.0 g

of O2 Sample 2 contains 2.0 g of H2 and 32.0 g of

O2 Are they the same compound?

Sample 1 contains 15.0 g of H2 and 120.0 g of O2 Sample 2 contains 2.0 g of H2 and 32.0 g of O2 Are they the same compound?

Sample 1 H2 : 15 x 100 = 11%15 g + 120 g = 135 g 135

O2 : 120 x 100 = 89% 135

Sample 2 H2 : 2 x 100 = 6%2 g + 32 g = 34 g 34

O2 : 32 x 100 = 94% 34

Different percentages so these are different compounds

Intro to the Periodic Table

Vertical columns Horizontal rowscalled groups or

families.

Elements in a group have similar chemical & physical properties.

Numbered from 1-18 from left to right

called periods.

Elements within a period have properties that change progressively across the table.

Metals – (left side) are good conductors of heat and electricity; shiny metallic luster (mostly silver or grayish white); malleable (hammered or rolled into thin sheets); ductile (string into a wire); properties vary according to groups

Nonmetals – (right side) elements that are poor conductors of heat and electricity, dull (no luster); some are gases at room temperature. Br is a liquid; C, P, Se, S & I are solid and much more brittle than metals

Metalloids – (on the stair-step line) – elements that have characteristics of both metals and nonmetals to a limited degree. Less malleable than metals, but not as brittle as nonmetals; some have luster, some don’t; semiconductors of electricity (used in semi-conducting materials found in computers, calculators, watches, TV’s and radios)

Branches of ChemistryOrganic Chem – study of carbon – containing

compoundsInorganic Chem – all substances not classified as

organic (mainly those that do not contain carbon)Physical Chem – the study of properties and changes

of matter and their relation to energyAnalytical Chem – identification of the components

and composition of materialsBiochemistry – substances and processes occurring

in living thingsTheoretical Chem – uses math and computers to

understand the principles behind observed chemical behavior and to design and predict new compounds

Scientific MethodScience- Body of knowledge gained through

systematic observation, experimentation, and study of the physical world.

Math- the language of Science: 16th century-Science made huge progress when it was discovered that nature can be analyzed and described when scientific findings are expressed mathematically they are easy to verify or disprove be experiment

Galileo Galilei (1564-1642) Italian PhysicistFrancis Bacon (1561-1626) English

philosopherCo-Founders of scientific method ~

Extremely effective in gaining, organizing, and applying new knowledge

Scientific method – systematic approach to do research, answer questions, and solve problems

Recognize a problemMake an educated guess-a hypothesis-about

the answerPredict the consequences of the hypothesisPerform experiments to test predictionsFormulate the simplest rule that organizes

the main ingredients: hypothesis, prediction, and experimental outcomes

http://www.youtube.com/watch?v=zrzMhU_4m-g