| A | B |
|---|
| Chemical formula | Way of writing the name of a compound using chemical symbols |
| subscript | Number written to the lower right of a chemical symbol in a chemical formula. It is the number of atoms of each element in the compound |
| valence electron | electron in the outermost energy level of an atom |
| oxidation number | Number of electrons an atom gains, loses or shares when it forms a chemical bond |
| Binary compound | Compound containing two elements |
| Polyatomic ion | group of atoms that acts as a charged atom, or ion, when combining with other atoms |
| Diatomic molecule | molecule made up of only two atoms |
| Formula mass | Sum of the mass numbers of all the atoms in a molecule or ions in an ionic compound |
| Atomic number | Number of protons in the nucleus of an atom |
| Protons | positively charged particles found in the nucleus |
| electron | negatively charged particles in an atom |
