1. Classifying Matter

2. ATOM
Atom – the smallest unit of an element that maintains the properties of that element.

3. Pure Substance
A sample of matter, either a single element or a single compound, that has definite chemical and physical properties
Figure 14, Page 22

4. Elements A pure substance that contains only one kind of atom
All atoms of the same element have the same atomic number

5. Compounds
A pure substance that is made up of two or more different elements joined by chemical bonds.

6. Molecules
The smallest unit of a substance that keeps all of the physical and chemical properties of that substance.

7. All of the following are molecules, but are they compounds or elements?
Br2
H2O O2 O3
C12H22O12
Compound
Element
Element
Compound

8. Mixtures
A combination of two or more substances that are not chemically combined.
Examples are air, ice tea, and even cake batter
The proportions of the substances can vary

9. Homogeneous Mixtures
have a uniform structure or composition throughout
any two samples taken will have the same proportions of ingredients
Examples: Gasoline, air, and syrup

10. Heterogeneous Mixtures
NOT evenly mixed.
Different regions will have different proportions
Examples: Pulpy Orange Juice, chocolate chip cookie dough, and granite.

11. Homogeneous and Heterogeneous Mixtures

13. Since mixtures are just physically combined, they can be separated.
Separating Mixtures
Since mixtures are just physically combined, they can be separated.

14. Separating Mixtures Some Methods include:
Filtering – separation of a mixture’s components through differences in particle size
Decanting – a fancy term for separating two components by pouring
Distillation – used to separate two liquids based on their differences in boiling points
Magnetism – used to separate magnetic substances
Evaporation – removing a liquid to leave a solid behind
Centrifuge – separates substances of different densities using a fast rotational motion
Chromatography – Separates two substances by using a mobile phase and a stationary phase

15. Physical Changes
A change of matter from one form to another without changing the substance itself.
A  A
Examples: phase changes, mixtures

16. Chemical Changes
when one or more substances change into entirely new substances with different properties
A + B  C (reactants go to products)

17. An Unexpected Color Change
Release or Absorption of Energy
Formation of a Precipitate (solid)
Formation of a gas

18. Chemical or Physical Frying an egg - Chemical Boiling Water - Physical
Sanding a wooden plank - Physical
Digesting food - Chemical
Popping a balloon - Physical