1. Matter anything with mass and volume Pure Substances can not be separated by physical means Mixtures can be separated by physical means Elements can not be broken down chemically or physically – only by nuclear means Compounds can be broken down chemically but not physically Heterogeneous Don’t look the same throughout Homogenous Look the same throughout Suspension ColloidSolution Diatomic If by itself, only exists as 2 atom molecules H 2, N 2, O 2, F 2, Cl 2, Br 2, I 2 Other elements Ex: mud water, pizza Large particles Positive Tyndall Effect Ex: milk, jello Medium particles Positive Tyndall Effect Ex: salt water small particles Negative Tyndall Effect Tyndall Effect – the scattering of light off of large enough particles.

2. Element vs. Compound Element: a substance that cannot be broken down physically or chemically. ex: Au, C, O 2 Compound: a substance made of two or more different elements bonded chemically. ex: NaCl, CO 2, H 2 O

3. Atom vs. Molecule Atom: the smallest unit of an element that retains its properties. ex: Au, C Molecule: a chemically bonded collection of two or more atoms. ex: NaCl, CO 2, H 2

4. Chemical Formula Formula indicating the types and number of each element in a compound. Ex: CO 2 indicates that one carbon atom is bonded to two oxygen atoms to form one molecule of carbon dioxide.

5. Are the following pure or mixtures? How many different substances are there? Are they elements or compounds? How many molecules and how many atoms?

6. H 2 O F 2 KMnO 4 Ca(OH) 2 2 Na 3 CO 2 + 6 Si + 2 H 2 O 5 Al 2 (SO 4 ) 3 Are the following pure or mixtures? How many different substances are there? Are they elements or compounds? How many molecules and how many atoms?