| 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 |
| valence 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 a metal ion and a non-metal ion |
| 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, typically a non-metal and non-metal |
| 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 | number of electrons lost, gained or shared when bonding occurs |
| electronegativity | the attraction an atom has for a shared pair of electrons |
| 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) |
| electrons | subatomic particles found in energy levels around the nucleus |
| sulfate | SO4 |
| ammonium | NH4 |
| hydroxide | OH |
| nitrate | NO3 |
| cation | a positive ion |
| anion | a negative ion |
| alkali metals | found in the Group 1 |
| alkaline earth metas | found in group 2 |
| noble gases | foud in Group 18 |
| halogens | found in Group 17 |
| transition elements | found in the drop down part of the periodic table |
| atomic number | equal to the number of protons |
| octet rule | most atoms need eight valence electrons to be stable |
