A salt, like calcium chloride, consists of many ions, in this case Ca^(2+) and Cl^-. If the salt is in its solid state you can't say with calcium and which chloride ions belong together, because they are in a crystal grid, and every positive ion is surrounded by negative ions in a certain proportion and vice versa. And this proportion (in the case of CaCl_2) is 1:2.
Note:
For sodium chloride NaCl it's a bit easier to visualize:
Every Na^+ ion has six Cl^- neighbours: above, below, left, right, in front and at its back. Same goes for every Cl^- ion. If you look through a NaCl crystal you will see Na-Cl-Na-Cl... in all three perpendicular directions.
