3 Types of pure substances ElementsCompoundSimplest, pure substance,One type of atom presentCan’t be broken down.Represented by symbols.Example: Na-Sodium Fe-Iron2 or more elements chemically combined.Represented by chemical formulas.Unique properties that are different from the elements that make it.Example: Water H2O
4 Types of Mixtures Mixtures 1. Made of more than one kind of pure substance.2. Can be separated or pulled apart physically ( they aren’t chemically combined)3. 2 types:HeterogeneousHomogeneous
6 Heterogeneous Mixtures 1. Not the same throughout.2. Large easily seen particles that can be separated out.3. Heterogeneous liquid mixtures are also known as suspensions.Settles after standing.Examples: salad, Italian dressing,
7 Homogeneous Mixtures Homogeneous Mixtures 1. Appears same throughout 2. Well mixed3. Will not completely settle upon standing,4. Tiny unrecognizable particles5. Homogenous mixtures are also called Solutions.Examples: Kool-aid
8 molecule: a group of atoms that are held together by chemical forces molecule: a group of atoms that are held together by chemical forces. Atoms that make up a molecule act as a unit.