| A | B |
|---|
| subscript | numbers in a chemical formula that tell how many atoms of each element are found in a unit of a compound. |
| Eight | all of the noble gases except helium have this number of electrons in their outer energy level |
| chemical bond | this is the force that holds atoms together in a compound |
| positive | an ion has this kind of charge when it has fewer electrons than protons |
| superscript | oxidation numbers are written as these |
| ionic bond | this is the force of attraction between the opposite charges of the ions in an ionic compound |
| neutral | the charge on a compound is always this |
| unequal | the ________ sharing of electrons in covalent bonds results in polar molecules |
| polar molecules | the unequal sharing of electrons in covalent bonds |
| equally | only two identical atoms can share electrons ________ |
| binary | a compound that contains only two different elements |
| oxidation number | tells how many electrons an atom must gain, lose, or share to become stable |
| zero | when writing chemcial formulas, write subscripts so that the sum of the oxidation numbers equals this |
| polyatomic ion | this always has a positive or negative charge |
| sulfate ion | the polyatomic ion SO4 |
