1. 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.

2. Classification of Matter
Matter – 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

3. 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)

4. Property
Physical or Chemical
Intensive or Extensive
Size P E
Density I
Color
Flammable C
N/A
Corrosive
Phase of matter

5. State (or phase) of matter is always a physical property: Solid, liquid, gas
Energy – move
Particle spacing
Volume
Shape
Compressible
Solid
Little
Close
Rigid
Definite No
Liquid
Some
Slide
Not Definite
Gas
Lot
Far
Not
Yes

6. Changes in Properties
Physical 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.

7. Chemical change- DOES change composition
Chemical change- DOES change composition. After a change has taken place a new substance appears
Changes 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.

8. Evidence of a chemical change:
Heat and/or light is produced
Production of a gas (bubbles)
Odor
Color change
5. Formation of a precipitate – a cloudy solid which appears after mixing to clear solutions

9. 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 ( )
Mass (of reactants) = Mass (of products)
Before After

10. 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)

11. Try it
Separating water turns into hydrogen gas and oxygen gas. If 10.0 g of hydrogen and 79.4 g of oxygen are produced, how much water did was there at the start?
____ g H2O  g H g O2
89.4 g H2O  g H g O2

12. 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

13. Mixtures are divided into two categories
1. 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: seawater, window glass, and air

14. Separating Mixtures (physical separation)
Filtration – through a porous barrier,
filters solids from liquids
Distillation – different boiling points
2 liquids: lowest boiling point vaporizes 1st
Crystallization – dissolved solids from a solutions
rock candy left after water evaporates
Chromatography – different rate of travel through a medium
identify chemicals, DNA testing, separates pigments, research

15. 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

16. Pure Substances are divided into two categories
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
1. Elements- substances composed of only one kind of atom (elements on the P.T.)
Ex: sodium ~ Na, Iron ~ Fe, Neon ~ Ne

17. Heterogeneous Mixture Suspension Element
Matter
Mixtures
Pure Substances
Homogeneous Mixture
Heterogeneous Mixture
Suspension
Element
Colloid-
Solutions
Compound

18. Heterogeneous Mixture Suspension Element
Matter
Has Mass
Has Volume(Occupies Space)
Mixtures
Pure Substances
Homogeneous Mixture
Heterogeneous Mixture
Suspension
Element
Colloid-
Solutions
Compound

19. Uniform Throughout (But Proportions can Vary)
Mixtures
Variable Composition
Can be physically separated
Homogeneous Mixture
Uniform Throughout (But Proportions can Vary)
Heterogeneous Mixture
Not uniform Throughout
Ex. Lumpy
Colloid-
Don’t settle out
Particles larger than molecule
Scatters light (Tyndall Effect)
Ex. Smoke, Fog
Suspension
Solid in Liquid
Eventually settle out
Ex. Muddy water
Wood, granite, blood
Solutions
Particles are atoms, ions, or molecules
Won’t scatter light
Ex. Salt Water, Steel, Air

20. Can’t be physically separated
Pure Substances
Definite Composition
Homogeneous
Can’t be physically separated
Element
Made of atoms
Cannot be further separated by chemical or physical means
(on periodic table Mendeleev arranged in
rows-periods
Columns- groups/families)
Compound
Chemical combinations of 2 or more atoms. (elements chemically bonded)
Cannot by separated by physical means (CaCl2, NaCl, Sugar, C6H12O6)

21. Heterogeneous Mixture Suspension Element
Matter
Has Mass
Has Volume(Occupies Space)
Mixtures
Pure Substances
Definite Composition
Homogeneous
Can’t be physically separated
Variable Composition
Can be physically separated
Homogeneous Mixture
Uniform Throughout (But Proportions can Vary)
Heterogeneous Mixture
Not uniform Throughout
Ex. Lumpy
Suspension
Solid in Liquid
Eventually settle out
Ex. Muddy water
Wood, granite, blood
Element
Made of atoms
Cannot be further separated by chemical or physical means
(on periodic table Mendeleev arranged in
rows-periods
Columns- groups/families)
Colloid- Don’t settle out
Particles larger than molecule
Scatters light (Tyndall Effect)
Ex. Smoke, Fog
Solutions
Particles are atoms, ions, or molecules
Won’t scatter light
Ex. Salt Water, Steel, Air
Compound
Chemical combinations of 2 or more atoms. (elements chemically bonded)
Cannot by separated by physical means (CaCl2, NaCl, Sugar, C6H12O6)

23. Law of Definite Proportions
Regardless of amount, a compound is always composed of the same elements in the same proportion by mass
% by Mass = Mass of element x 100 Mass of compound
If compounds have the same % by mass, they must be the same
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

24. % iron = 7g x 100 = 70% 10 g %oxygen = 3g x 100 = 30% 10g
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

25. Try it Sample 1 contains 15.0 g of H2 and 120.0 g of O2
Are they the same compound?

26. Sample 1 contains 15.0 g of H2 and 120.0 g of O2
Are they the same compound?
Sample 1 H2 : 15 x 100 = 11%
15 g g = 135 g
O2 : 120 x 100 = 89%
135
Sample 2 H2 : 2 x 100 = 6%
2 g + 32 g = 34 g
O2 : 32 x 100 = 94% 34
Different percentages so these are different compounds

27. Intro to the Periodic Table
Vertical columns
Horizontal rows
called 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.

28. 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)

29. Branches of Chemistry
Organic Chem – study of carbon – containing compounds
Inorganic 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 energy
Analytical Chem – identification of the components and composition of materials
Biochemistry – substances and processes occurring in living things
Theoretical Chem – uses math and computers to understand the principles behind observed chemical behavior and to design and predict new compounds