| A | B |
|---|
| valence electron | Electrons in the outermost shell that determines bonding |
| atomic mass | the mass of an atom |
| strong force | holds the nucleus together. keeping the protons and neutrons together |
| atomic number | the number of protons found in an element |
| element | the pure substance whose atoms all have the same atomic number |
| neutron | particles that do not have a charge and are neutral |
| electrons | particles that have a negative charge |
| proton | particle that has a positive charge |
| atom | the building blocks of matter, made of protons, neutrons and electrons |
| shells | energy levels where the electrons are found |
| nucleus | the center of the atom, contains protons and neutrons |
