| A | B |
|---|
| chemical formula | shows elements and their numbers in a compound |
| polyatomic ion | group of atoms that acts as one charged atom |
| subscripts | show numbers os atoms in a compound |
| covalent bond | bond formed by sharing electrons |
| oxidation number | number of electrons lost or gained or shared |
| eight | number of electrons needed in the outer level of most atoms to make them stable |
| zero | the sum of the oxidation numbers in a compound |
| sodium chloride | NaCl |
| superscript | number that shows oxidation number |
| Ca(OH)2 | compound with 5 atoms |
| NaOH | compound with 3 atoms |
| Al(NO3)3 | compound with 13 atoms |
| hydrate | crystalline substance that contains water |
| polar molecule | a molecule with partially charged ends |
| ion | a postively or negatively charged atom |
| cation | positive ion |
| anion | negative |
