| A | B |
|---|
| Atom | the smallest unit of an element that still have the properties of that element. |
| Element | Cannot be broken down into simpler substances |
| Proton | one unit of positive charge—has same mass as neutron |
| Neutron | neutral (no charge) particles with the same mass as a proton |
| Nucleus | Formed by protons and neutrons-- Electrons orbit around this |
| Electron | A particle located in the space orbiting the nucleus that have one unit of negative charge (and little mass) |
| Molecule | A particle with 2 or more atoms bonded together |
| Covalent Bond | A chemical bond that is formed by the sharing of electrons |
| Valence Electron | Found in the outermost electron orbital of atom |
| Ionic Bond | Bond created by the force of attraction between two ions |
| Ion | any atom that has an excess charge (positive or negative) |
| Isotope | Varieties of an element that differ only in the # of neutrons in the atomic nucleus |
