| Sodium is in the first column of the periodic table, so it loses one
electron and becomes a sodium ion with a +1 charge. Chlorine is a nonmetal in the next to
the last column. Because it is a nonmetal, it will tend to gain electrons, and it will
gain as many electrons as it needs to fill up its outermost energy level. There's room for
only one more electron so it will take on a -1 charge and is called a chloride
ion. So we have a +1 charge for sodium and a -1 charge for chlorine. The charges are
opposite but equal; therefore, there is a 1:1 ratio of sodium ions to
chloride ions and NaCl is the formula of the compound. (The name of this ionic compound is
sodium chloride because it is made of sodium ions and chloride ions.) |
| Ions |
Na+ |
Cl- |
| Charge ratio |
1 |
1 |
| Ion ratio |
1 |
1 |
| Formula |
NaCl |
| Name |
sodium chloride |
|
