| Term | Definition |
| ion | an atom or group of atoms that has an electric charge |
| polyatomic ions | ions that are made of more than one atom |
| ionic bond | form as a result of the attraction between positvie and negaive ions |
| ionic compound | compound that consists of positive and negative ions; i.e. sodium chloride |
| chemical formula | combination of symbols that shows the ratio of elements in a compound |
| ionic compound | brittle crystal that has a high melting point and when dissolved in water or melted, conducts electricitly |
| crystal | orderly 3-dimensional arrangement form by ions |
| covalent bond | form when tow aroms share electrons |
| molecule | a neutral group of atoms hoined by covalent bonds |
| double bond | atoms that share two pairs of electrons |
| triple bond | atoms that share three pairs of electrons |
| molecular compound | contains atoms that are covalently bonded |
| molecular compound | has lower melting point and does not conduct electricity when dissolved in water |
| polar bond | covalent bond in which electrons are shared unequally |
| nonpolar bond | valence electrons are share equally |