| A | B |
|---|
| Atom | basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. |
| Nucleus | the dense, central part of an atom containing positively charged protons, and neutrally charged neutrons |
| Proton | positively charged subatomic particle found in the nucleus of an atom |
| Subatomic particle | particles that make up an atom. Examples are protons, electrons, and neutrons |
| Neutron | neutrally charged subatomic particle found in the nucleus of an atom |
| Electron | negatively charged subatomic particle found orbiting around hte nucleus of an atom |
| Valence electrons | electrons found in the outermost energy level of an atom which will determine how reactive an atom will be. |
| Atomic number | the number of protons found in the nucleus of an atom |
| Atomic mass | the mass of one atom of a specific element. It can be determined by finding the sum of protons and neutrons in an atom. |
| Orbitals/Rings/Shells/Energy levels | terms that refer to the location of electrons in an atom. |
