1. Chemistry 2

2.  Physical Change – ◦ One example of a physical change is  Chemical Change – ◦ One example of a chemical change is

3.  Sometimes these are called elements, this is because these materials are made of only 1 type of element ◦ consists of only one kind of atom ◦ cannot be broken down into a simpler type of matter by either physical or chemical means ◦ can exist as either atoms or molecules  Atoms – one singular atom by itself  Ex. Nobel Gases – He, Ne, Ar, Xe  Molecules - more than one atom bound together  Ex. Nitrogen gas – N 2

5.  Compounds are substances that consist of two or more substances bound together. ◦ can be broken down into a simpler type of matter, or elements, by chemical means, but not by physical means ◦ has properties that are different from its component elements ◦ always contains the same ratio of its component atoms.  Ex. Carbon Dioxide, CO 2 ; Water, H 2 O

7.  Mixtures are substances that consists of two or more different elements or compounds physically intermingled ◦ can be separated into its components by physical means, and ◦ often retains many of the properties of its components. ◦ Ex. Salt water, H 2 O + NaCl ◦ Air, N 2 + O 2

9.  Heterogeneous Mixture – Mixture where particles are not evenly mixed together ◦ You can see different layers ◦ May be separated by phase: Solid in liquid ◦ Ex. Salad Dressing  Homogenous Mixture – Mixture where particles are evenly mixed together ◦ Can not see layers ◦ Looks the same throughout. ◦ Ex. Kool-Aid