This document classifies matter based on purity and composition. It discusses pure substances like elements and compounds that have a definite composition and properties that cannot be altered through physical means. Mixtures are less pure and have a variable composition, consisting of two or more pure substances that are either homogenously mixed at the atomic level or heterogeneously mixed in an uneven distribution where the parts can be seen.

1. Classification of Matter

2. Classification of Matter One way chemists classify matter is based on its purity .

3. Classification of Matter Pure Substance – Matter that has only 1 set of chemical and physical properties. HAS DEFINITE COMPOSITION, Example: Pure water always has the exact same chemical and physical properties under the same conditions. If water ever tastes different then it isn’t pure water; it fits into our next category.

4. Classification of Matter Mixture – Two or more puRe substances mixed together. Each substance in the mixture retains its own set of chemical and physical properties. HAVE VARIABLE COMPOSITION Example: Copper and Zinc can be mixed together to produce brass.

5. Mixtures Can be Homogeneous or heterogeneous. Heterogeneous mixture – Uneven distribution of substances. (Very impure) - You can see the different parts. Examples: Sand Granite Wood

6. Mixtures Homogeneous Mixture – Components are evenly mixed. Salt water contains salt and water, but are mixed all the way to the atomic level - Cannot see the parts. , but it can still be separated by physical means. Seawater distillation plant

7. Pure Substances Compound – Two or more elements chemically bonded together. Examples: Carbon Dioxide (CO 2 ) Water (H 2 O) Salt (NaCl) Sucrose (C 12 H 22 O 11 )

8. Pure Substances Compounds have only 1 set of properties . They cannot be separated by any physical process. - Can only be separated by a chemical reaction . Water can be separated into Hydrogen and Oxygen by a process called Electrolysis.

9. Pure Substances Elements – Substances made up of only one type of atom. - Cannot be separated by any physical OR chemical process. Examples: Carbon Helium Gold

10. Matter Mixture Pure Substance Element Compound Heterogeneous Mixture Homogeneous Mixture Can be separated physically Cannot be separated physically Can see the parts Cannot see the parts Can be separated chemically Cannot be separated Most impure Most pure