| A | B |
|---|
| chemical formula | a precise statement that tells which elements are in a compound and their ratios |
| chemically stable | an atom whose outer energy level is completely filled with electrons (usually an octet) |
| chemical bond | the force that holds together the atoms in a compound |
| valance electron | an electron in the outer energy level of an atom |
| dot diagram | a diagram used to represent the electrons in the outer energy level of an atom |
| ion | a positively or negatively charged atom |
| ionic bond | a type of chemical bond formed by the attraction between opposite charges of the ions in a ionic compound |
| subscript | a number in a chemical formula that tells how many atoms are present |
| superscript | a number that represents the charge on an ion |
| coefficient | a number in a chemical formula that tells how many molecules are present |
| covalent bond | a type of chemical bond formed by atoms when they share electrons |
| polar molecule | a covalent bond in which the electrons are shared unequally (creates oppositely charged ends) |
| nonpolar molecule | a covalently bond in which the electrons are shared uequally (no charged ends) |
| oxidation number | a positive or negative number that indicates how many electrons an atom has lost, gained, or shared when bonding with other atoms |
| binary compound | a chemical compound composed of two elements |
| polyatomic ion | a group of covalently bonded atoms in which the whole group is positively or negatively charged (behaves chemically as if it is a single atom) |
| hydrate | a compound that has water molecules attached to its ions |
| sulfate | SO4 |
| ammonium | NH4 |
| hydroxide | OH |
| nitrate | NO3 |
| anhydrous | without water |
