1. Classifying Matter Matter Elements Compounds Mixtures
Scientists classify matter according to make-up.
Matter
Elements
Compounds
Mixtures

2. Elements Simplest pure substance – fixed composition.
Pure substance is made of only one material. Same throughout. Referred to as homogeneous matter.
Are made of alike atoms, which are the basic building blocks of matter.
Represented by chemical symbols - H, O, Al, Cu, Au.
118 elements organized in the periodic table in squares called an element key.

3. Element Key Atomic Number I.D’s the element Symbol Element Name
Atomic Mass
I.D’s the element
represents elements
mass of element (amu’s)

4. Elements/Symbols Calcium Tin Uranium Magnesium Phosphorus Iron iodine
Silver
Helium
Mercury
Nickel
Silicon
Sulfur
Copper
Chromium
Aluminum
Bromine
Hydrogen
Zinc
Potassium
Oxygen
Lead
Lithium
Gold
Fluorine
Neon
Nitrogen
Sodium
Carbon
Chlorine

5. Compounds Two or more elements chemically combined.
Represented by chemical formulas.
Examples: H2O, CO2, NaCl, C12H22O11
Molecules are the smallest natural unit of a compound or diatomic element. A molecule is made up of two or more atoms chemically combined.

6. Chemical Formulas
Combination of chemical symbols that represents compounds.
Sometimes represents a molecule of an element. Example: O2, N2, Cl2 called diatomic elements – two atoms of the same element.
Subscripts are the # of atoms of an element - H2O
Coefficients are the # placed in front of chemical formula. Represents # of molecules of a compound H2O

7. Identifying Substances
Element
or Compound
Symbol or Formula
Atom
or Molecule
Fluorine (F)
Water (H2O)
Chlorine gas (Cl2)
Element
Symbol
Atom
Compound
Formula
Molecule
Element
Formula
Molecule

8. Found in milk of magnesia
Counting Atoms
Name
Use
Formula
Atoms in Formula
Calcium carbonate
Chalk
CaCO3
Magnesium hydroxide
Found in milk of magnesia
Mg(OH)2
Phosphoric acid
Detergents
3H3PO4
Trinitrotoluene (TNT)
Explosive
2C7H5(NO2)3
Ca=1
C=1
O=3
Mg=1
O=2
H=2
H=9
P=3
O=12
C=14 N=6
H=10 O=12

9. Calculating Formula Mass
Formula mass of a compound is the sum of the atomic weights of all atoms in a chemical formula.
Examples: Atoms Atomic Mass Totals
H2O 2 of H x
1 of O x
18.0 amu
C12H22O of C x
22 of H x
11 of O x
342.0 amu

10. Mixtures
Two or more substances mixed together but not chemically combined.
Has unlike parts and a composition that varies from sample to sample.
Properties:
Sub. in a mixture keep their separate identities.
Sub. can be present in any amount.
Sub. can be separated out by physical means.

11. Mixtures

12. Heterogeneous Mixtures
The least-mixed.
Doesn’t appear to be the same throughout.
Particles large enough to be seen.
Examples: sand, dirt, concrete, suspensions, etc.

13. Homogeneous Mixtures Well-mixed. Same throughout a given sample.
Examples: air, soda, toothpaste, lotions, etc.

14. Solutions A homogeneous mixture.
One substance dissolves in another. Solutions remain constantly & uniformly mixed.
Examples: lemonade, soda, ocean water, antifreeze, metal alloys (steel, brass), etc.

15. Colloids A homogeneous mixture. Mixed together but not dissolved.
Appears cloudy. Scatters light.
Examples: milk, cool whip, toothpaste, lotions, fog, paint, etc.

16. Composition of Matter