| A | B |
|---|
| nucleus | the central core of the atom, containing protons and usually neutrons |
| proton | small positively charged particles that are found in the nucleus of an atom |
| neutron | small uncharged particles that are foun in the nucleus of an atom |
| electron | negatively charged, high-energy particles that move around the outside the nucleus of an atom |
| atomic number | the number of protons in the nucleus of an atom |
| group | elements in the same vertical column of the periodic table. Also called family |
| family | elements in the same vertical row of the periodic table |
| period | elements in the same horizontal column of the periodic table also called group |
| halogen | an element belonging to group 17 of the periodic table |
| crystal | an orderly, three-dimensional pattern of ions or atoms in a solid |
| mineral | a naturally occurring solid that has a crystal structure and a definate chemical composition |
| ion | an atom or group of atoms that has become electrically charged Loser=positive ion/charge, gainer=negative ion/charge |
| ionic bond | the attraction between oppositely charged ions. Electrons are lost+ or gained-. "left are losers" "right will win" |
| polyatomic ion | ions that are made of more than one atom that react as one. (CO3) |
| covalent bond | when two atoms share electrons. Often form between two or more nonmetals (CO2) |
| double bond | a chemical bond formed when atoms share two pairs of electrons. |
| molecular | a compound consisting of molecules of covalently bonded atoms. Properties: lower melting point and boiling point. Poor conductors of electricity |
| compound | a substance made of two or more elements chemically combined in a specific ration or proportion (H2O, NaCl) |
| polar | the description of a covalent bond in which electrons are shared unequally, or of a molecule containing polar bonds that do not cancel out. +H:F:- |
| nonpolar | the description of a covalent bond in which electrons are shared equally; or of a molecule containing nonpolar bonds, or polar bonds that cancel out :F:F: |
| electron dot diagram | a representation of the number of valence electrons I an atom, using dots placed around the symbol of an element Be: |
| valence electron | the electrons that are farthest away from the nucleus of an atom and are involved in chemical reactions |
