| Anion | a negatively charged ion. |
| Cation | a positively charged ion |
| Covalent bond | a chemical bond formed by the sharing of a pair of electrons between atoms |
| Double bond | a covalent bond in which two pairs of electrons are shared by two atoms |
| Electronegativity | a measure of the ability of an atom in a molecule to draw bonding electrons to itself |
| Ion | an electrically charged particle obtained from an atom or a chemically bonded group of atoms by addin- or removing zn electrons |
| Ionic bond | a chemical bond formed by the electrostatic attraction between positive and negative ions |
| Lewis electron-dot system | a formula using dots to represent valence electrons |
| Octet rule | the tendency of atoms in molecules to have eight electrons in their valence shells (two for hydrogen atoms). |
| Polar covalent bond | a covalent bond in which the bonding electrons spend more time near one atom than near the other |
| Resonance | a representation in which we describe the electron structure of a molecule, having delocalized bonding by, writing all possible electron-dot formulas |
| Triple bond | a covalent bond in which three pairs of electrons are shared by two atoms |
| Valence electron | an electron in an atom outside the noble gas or pseudo-noble-gas core |