| A | B |
|---|
| molecule | a neutral chemically bonded group of atoms that act as a unit |
| molecular compound | a compound that is composed of molecules |
| ion | an atom or group of atoms that has a positive or negative charge |
| cation | any atom or group of atoms with a positive charge |
| anion | any atom or group of atoms with a negative charge |
| ionic compound | a compound composed of positive and negative ions |
| chemical formula | shows the number and type of atoms present in the smallest representative unit of a substance |
| molecular formula | a chemical formula that shows the actual number and kinds of atoms present in a molecule of a compound |
| formula unit | the lowest whole-number ratio of ions in an ionic compound |
| law of definite proportions | in any sample of a chemical compound, the elements are always combined in the same proportion by mass |
| law of multiple proportions | whenever 2 elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers |
| monatomic ions | a single atom with a positive or negative charge as a result of losing or gaining valence electrons |
| polyatomic ions | a tightly bound group of atoms that behaves as a unit and carries a charge |
| binary compounds | a compound composed of 2 elements |
| ternary compound | a compound containing atoms of three different elements, usually containing at least one polyatomic ion |
