| A | B |
|---|
| atomic mass | mass of an atom expressed in amu's |
| electron cloud | region where electrons are likely to be found |
| proton | positively charged subatomic particle of an atom |
| atom | smallest unit of an element; maintaining the chemical properties of that element |
| mass number | sum of protons and neutrons |
| atomic mass unit | SI unit used to express the masses of atomic paticles |
| electron | negatively charged particles of atoms |
| atomic number | number of protons in nucleus of an atom |
| isotope | atoms having the same number of protons, different number of neutrons |
| nucleus | central region of an atom; protons and neutrons |
| neutron | particles of an atomic nucleus having no charge |
