| A | B |
|---|
| ion | an atom that is electrically charged because it has lost or gained electrons |
| valence | the number of electrons an atom borrows or lends |
| formula | a short way or writing the name of a compound |
| polyatomic ion | a charged group of atoms that acts line the ion of a single atom |
| hydroxide ion | an ion containing one oxygen atom and one hydrogen atom |
| diatomic molecule | a molecule containing two atoms of the same elements |
| formula weight | the sum of all the atomic weights in a molecule |
| molecular weight | the same as formula weight |
| subscript | a number that shows how many atoms of an element are in a molecule |
| chemical equation | a description of a chemical reaction using symbols and formulas |
| coefficient | a number that tells how many moleculees of a substance take part in a reaction |
