1. Elements and Compounds
And distinguishing between atoms and molecules

2. ELEMENTS Pure substances Cannot be decomposed
The building blocks of all matter
There are 113 known elements

3. Examples

4. COMPOUNDS Pure Substance Made from combining elements
Not all combinations of elements are compounds, some are mixtures
Can be decomposed into simpler substances
Have a definite composition
a fixed number of elements

5. Examples

6. ATOMS The smallest possible unit of an element
An element only contains one type of atom

7. MOLECULES Particles made of two or more atoms
The smallest particle of a substance that retains the properties of the substance

8. Heterogeneous Mixture
Self Check
Homogeneous Mixture
Compound
Heterogeneous Mixture
Homogeneous Mixture
Compound

9. Classifying Matter No Uniform Properties?? Yes Fixed Composition? Yes
Compound
Heterogeneous No
Uniform Properties??
Yes
Fixed Composition?
Yes No
Yes
More than one element?? No
Homogeneous
Element