| A | B |
|---|
| Matter | anything that takes up space and has masss |
| Atom | smallest part of an element that has the properties of that element |
| Electron | subatomic particle with a negative charge |
| Proton | subatomic particle with a positive charge |
| Neutron | subatomic particle with a neutral charge |
| Atomic number | Number of protons in the nucleus of an atom, identifies element. |
| Atomic Mass | Number of protons added to the number of neutrons |
| Nucleus | Area of an atom, Location of the protons and neutrons |
| Energy Level | Location of electrons |
| Reactivity | Chemical property of an element, determined by number of electrons. |
