| A | B |
|---|
| Element | A substance consisting of atoms which cannot be broken down further without losing their properties. |
| Atom | The smallest object that retains properties of an element. |
| Proton | A subatomic particle with a positive charge |
| Neutron | A subatomic particle with a neutral charge |
| Electron | A subatomic particle with a negative charge |
| Electron Cloud | The system of electrons surrounding the nucleus of an atom. |
| Nucleus | The positively charged center of the atom containing protons and neutrons. |
| Atomic Number | The number of protons in an element. The identifying number of an element. |
| Atomic Mass (Mass Number) | The average mass of the nucleus of all isotopes of an element. |
| Isotope | Elements that have the same number of neutrons, but a varying number of neutrons. (Ex. C14 and C16) |
