1. Matter and Change
Ch. 2

2. Matter
2-1

3. Are the following considered matter?
Key Terms
Chemistry: explains the structure and properties of matter
Matter: anything that occupies space and has mass
Mass: amount of matter an object contains
Are the following considered matter?
Car, pencil, heat, thoughts/ideas, light, air, radio waves, water, cell

4. States of Matter Most common states of matter:
Solid: particles in fixed position, tightly packed; definite shape and volume.
Liquid: particles tightly packed but can slide past each other; fixed volume but changing shape.
Gas: particles in constant state of motion and rarely stick together; shape and volume change.

5. Pure Substances
2-2

6. Pure Substances
Pure substance: matter with a uniform and definite composition; contains 1 kind of matter
Cannot be separated physically
Ex: gold (Au), sugar/sucrose (C12H22O11), water (H2O), carbon dioxide (CO2)

7. Types of Pure Substances
Compound
2 or more elements combined
Can be broken down into simpler substances chemically
Ex: salt (NaCl), baking soda (NaHCO3), sugar(C6H12O6), caffeine, water (H2O)
Element
Simplest form of matter
Cannot be broken down any further by chemical or physical means!!
Represented on periodic table of elements
Ex: oxygen (O2), pure gold (Au), iron (Fe)

8. Symbols and Formulas
Chemical Symbol: each element is represented by one- or two- letter’s.
First letter is always capitalized.

9. Chemical Formula: shows which elements are in a compound and how many of each.
Numbers in subscript show the # of atoms of each element
Ex: sugar C6H12O6
water H2O
carbon dioxide CO2
6 carbon atoms,
12 hydrogen atoms, and
6 oxygen atoms

10. Mixtures
2-3

11. Mixture Mixture Made up of 2 more substances
Can be physically separated
Ex: salt water, lemonade, chocolate milk, dinner salad, blood

12. Classifying Mixtures Homogenous: Heterogeneous:
Same throughout, completely dissolved
Called a solution
Ex: Sugar water, air, steel, tableware (sterling silver), salt water
Heterogeneous:
Different compositions within the mixture
Ex: orange juice, granite rock, blood

13. Separating Mixtures Mixtures are separated through physical means.
Magnetism to separate metal filaments
Filtration to separate solid from liquid
Distillation = liquid is boiled separating vapor from liquid or solid substance

14. DRAW!

15. Physical + Chemical Changes
2-4

16. Physical Property
Physical Property: quality or condition of a substance that can be observed or measured without changing the substance’s composition
Includes color, solubility, odor, hardness, density, melting point, boiling point
Ex: water is clear, has no odor, density is 1g/ml, boils at 100°C

17. Physical Changes
Physical Change: is a change of matter from one form to another without changing its identity.
Includes dissolving (mixing), crushing, melting, freezing, evaporating, bending, cutting
It is reversible!!!
Ex: Breaking a piece of chalk into two, getting your hair cut, melting ice, crushing aluminum can, mixing oil and vinegar

18. Physical Changes

19. Chemical Changes
Chemical reactions occur when substances undergo chemical changes to form new substances
They are irreversible!
Signs of a chemical change:
Gas produced (bubbling)
Odor produced (gas)
Color change
Rusting
Burning
Precipitate (solid) formed
Reactivity (one chemical reacts with another)
Energy (light, heat, cold) released or produced

20. Chemical Equation 4H2 + O2  2H2O  means “yields”
Reactants = substance starting a reaction, on left side of arrow
A + B  C
Iron + sulfur  iron sulfide
Products = substance formed in a reaction, on the right side of the arrow

21. Conservation of Mass
Law of Conservation of Mass = matter is neither created nor destroyed…
Thus, mass of reactants = mass of products
Atoms in a chemical reaction don’t change, they rearrange!
The same number of each kind of atom must be on the left side as well as the right!
Ex: H2CO3(aq) H2O(l) + CO2(g)
H = 2, C =1, O = 3
H = 2, C =1, O =3