1. Classifying Mixtures
A mixture is a physical blend of two or more substances.
Two Types:
Heterogeneous
Homogeneous
Heterogeneous: not uniform in composition (ex. a salad)
Homogeneous: completely uniform in composition (ex. salt water)
homogeneous mixtures are called solutions
Solutions:
have the same composition throughout and can be gases, liquids, or solids. Any part of a system with uniform composition and properties is called a phase
Types of Solutions
Liquid-Gas
Liquid-Liquid
Solid-Liquid
Solid-Solid
Gas-Gas
Gas-Liquid

2. Elements & Compounds
Elements: smallest form of matter that can exist under normal laboratory conditions, elements cannot be separated into simpler substances~ Building Blocks
Compounds: Two or more elements combine with one another to form compounds. Compounds are substances that can be separated into simpler substances only by chemical means. (Ex. if you burn sugar, it eventually turns black, breaking down into carbon and water vapor. Water can still be broken down, so it is a compound. Carbon cannot, so it is an element.)

3. Fermentation of Sugar
Gay Lussac discovered the general chemical equation for the breakdown of sugar into ethanol and carbon dioxide:
C6H12O6---- 2CH3CH2OH + 2CO2

4. Chemical Symbol
Chemical Symbol: each element is represented by a one or two letter chemical symbol
Examples: C, N, O, H, Na, Cl, F, Mg, S

5. Review Which of the following are Homogeneous? Heterogeneous?
(a) spaghetti sauce
(b) glass
(c) muddy water
(d) cough syrup
(e) mixture of nitrogen gas and helium gas
Hetero
Homo

6. Review Name the type of solution (a) Sodium Chloride in water (brine)
Types of Solutions
Liquid-Gas
Liquid-Liquid
Solid-Liquid
Solid-Solid
Name the type of solution
(a) Sodium Chloride in water (brine)
(b) Copper in Silver (sterling silver alloy)
(c) Water vapor in air (moist air)
(d) Acetic acid in water (vinegar)
Answers
a. Solid-Liquid
b. Solid-Solid
c. Liquid-Gas
d. Liquid-Liquid

7. Review What would be an example of a Gas-Gas solution?
What would be an example of a Gas-Liquid solution?
Carbon dioxide and oxygen in nitrogen (air)
Carbon dioxide in water

8. Review Classify each of the following as a substance or a mixture
(a) silver
(b) alphabet soup
(c) textbook
(d) table salt (NaCl)
(a) substance
(b) mixture
(c) mixture
(d) substance

9. Review How do you distinguish between an element and a compound?
Compounds can be separated by physical means into elements; elements cannot be separated into simpler substances by chemical techniques
Compounds can be separated by chemical means into elements; elements cannot be separated into simpler substances by chemical techniques
Compounds can be separated by physical means into elements; elements can be separated into simpler substances by chemical techniques
Compounds can be separated by chemical means into elements; elements can be separated into simpler substances by chemical techniques

10. Review What is the chemical symbol for each of the following elements?
Copper C Cu Co Cd
Phosphorus Pb Sn P Po
Silver S Se Sn Ag
Sodium Sb Na

11. Review Name the chemical elements represented by the following symbolsSn
Lead
Tin
Sulfur Ca
Cadmium
Calcium
Chlorine S
Sulfur
Tin
Selenium