1. Atoms, Elements, & Compounds

2. Elements Element --- any substance that can’t be broken down into simpler substances. Example of an element --- Oxygen, nitrogen, hydrogen, helium… An element is made up of only one kind of atom.

3. Atoms Smallest particle of an element Atoms are made of smaller parts ---- protons, neutrons, and electrons Protons ----- positively charged Neutrons ---- no charge (neutral) Electrons ---- negatively charged Protons and Neutrons found in the nucleus --- NOT ELECTRONS

4. Atoms have mass – this is equal to the number of protons and neutrons. (Atomic mass) Atomic number = the number of protons.

5. What’s a compound? Compound --- 2 or more elements combined together. Held together by bonds. Most common compound --- Water! Water is made up of the elements hydrogen and oxygen. Molecule --- smallest unit of a compound.