1. Classification of Matter
I. Describing Matter
Physical Property
General Property
Chemical Property
Physical Change
Chemical Change

2. A. Physical Property
A characteristic of a substance that can be observed or measured without changing its identity.
can be used to separate mixtures
Viscosity- resistance to flowing
Greater viscosity, slower it moves
Honey vs. water
Decreases when heated

3. Physical Properties Conductivity- ability to conduct heat
Metals have high conductivity-wood bad
Usually good conductors of electricity
Malleability- ability of a solid to be hammered without shattering
Most metals are malleable
Hardness- the resistance of a
substance to scratching
Knife (stainless steel) & diamonds

4. Physical Properties
Melting Point- temperature at which a solid turns to a liquid
Boiling Point- temperature at which a liquid turns to a gas
Density- mass per unit
volume

5. Why do we use Physical Properties?
Identification of unknown substances:
-Crime scenes
-Chemists, researchers
Choosing the right material:
-frying pan- use metal, not wood
Separating mixtures:
-filtration- process that separates
materials based on the size of the particles
-distillation- process that separates
substances in a solution based on their
boiling points
Ex. Converting sea water to fresh water
BP salt= 1465 C BP of water= 100 C

6. General Properties of Matter
All objects have these 4 properties:
1. Mass- amount of matter in an object -g
2. Volume- amount of space an object
takes up
-L, mL, and cm3
3. Density- the amount of matter in a given
space
-D=m/v -g/mL or g/cm3
4. Weight- the force of gravity acting on an object
- W=mg = kgm/s2 = N

7. Weight
Ex) A student’s weight is 694 N on Earth. What will her weight be on the moon if the moon’s gravity is 1/6th that of the Earth’s?
W= mg W mg
Given: W = 694 N
m= W/g
m= 694 N / 9.8 m/s2 = 71 kg
g = 9.8 m/s2 on Earth
g on moon = (9.8 m/s2)(1/6)=1.6 m/s2
W=mg
W= (71 Kg) (1.6 m/s2) = 110N

8. Chemical Property
Any ability to produce a change in the composition of matter
Change into a new substance
1. Flammability- ability to burn-paper, gas
2. Reactivity- how readily a substance combines chemically with other substances
-oxygen- highly reactive-reacts
with iron & water to form rust

9. Classes of Matter Elements, Compounds, Mixtures
A. Pure Substances:
Elements- simplest pure substance
-homogeneous (same)
-can’t be split or changed into simpler
substances
-Ex. Oxygen, Nitrogen, Copper
atom- smallest particle of an element
-made up of subatomic particles
a) all elements are made up of atoms
b) atoms of the same element are the same
c) atoms of different elements are different
chemical symbol- a shorthand way to represent an element
- H, O, N , Cu

10. 2. Compound
matter composed of 2 or more elements in a fixed ratio-chemically combined
properties differ from those of individual elements
Ex. Water= H fuels fire, O keeps it burning
Can be broken down by chemical means (heat, electric current, etc.)
EX: salt (NaCl), sugar (C12H22O11), H2O

11. Molecule- smallest particle of a
Molecule- smallest particle of a compound that has the properties of the compound
-some elements exist as diatomic molecules
-H2, O2, N2, Cl2, F2

12. Chemical Formulas
Combination of chemical symbols
Symbols of the kind of elements in a compound
# of atoms of each element
Ex) H2 = 2 atoms of Hydrogen
2– subscript
H2O = 2 atoms of Hydrogen, 1 atom Oxygen
H2SO4= 2 atoms of Hydrogen, 1 atom Sulfur, 4 atoms of
Oxygen
Coefficient- the # in front of the symbol or compound – tells how many molecules
Ex) 2H2O = 2 molecules of water
-each contains 2 atoms of H, 1 atom O
2(H2O) = Total of 4 Hydrogen and 2 Oxygen
a) 4HCl b) 4H2SO4 c) (NH3)2 d) (H2O)2

13. 3. Mixtures 2 or more pure substances mixed together.
No chemical combination or rxn
No new substances are formed
Have properties of substances forming it: Salt water= salty & wet
Homogeneous Mixture (Solution)
even distribution of components
very small particles
Cannot be filtered or
scatter light
particles never settle
EX: saline solution, alloy-metal
solution-solid dissolved in solid
Brass= copper + zinc

14. 3. Mixtures Heterogeneous mixtures: Uneven distribution of
components- EX: granite
Colloids & suspensions
Suspension
large particles
particles scatter light, can be filtered
particles will settle (needs to be shaken)
EX: fresh-squeezed lemonade, saw dust in air

15. C. Mixtures Colloid medium-sized particles
particles scatter light (looks cloudy), cannot be filtered
particles never settle
EX: milk, fog-water droplets
in air

16. Can it be separated by physical means?
A. Matter Flowchart
MATTER
yes no
Can it be separated by physical means?
MIXTURE
PURE SUBSTANCE
Is the composition uniform? no
yes
Can it be decomposed by chemical means? no
yes
Homogeneous Mixture
(solution)
Heterogeneous Mixture
Compound
Element

17. B. Physical Change
A change in the form of a substance without changing its identity.
properties remain the same
Some are reversible
can be used to separate mixtures
EX: dissolving, grinding, cutting paper, cut/braid hair, freeze water

18. C. Chemical Change A change in the identity of a substance.
properties change
one or more new substance is formed
irreversible
Signs: a) color change (patina)
b) formation of a gas- baking soda +
vinegar- carbon dioxide
c) release of light/heat –
d) precipitate- solid that forms &
separates from a liquid-
lemon juice + milk- curdles
EX: burning, rusting