A salt, like calcium chloride, consists of many ions, in this case Ca^(2+)Ca2+ and Cl^-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_2CaCl2) is 1:2.
Note:
For sodium chloride NaClNaCl it's a bit easier to visualize:
Every Na^+Na+ ion has six Cl^-Cl− neighbours: above, below, left, right, in front and at its back. Same goes for every Cl^-Cl− ion. If you look through a NaClNaCl crystal you will see Na-Cl-Na-Cl... in all three perpendicular directions.
