Question

What is the formula of calcium chloride?

Answer 1

See below...

Explanation:

Calcium chloride is an ionic compound.

`therefore` it is made of ions. As we know, ions can i have `+` or `-` charge but the key idea is that the overall charge of an ionic compound has to balance out to be neutral.

Calcium is in group 2 `therefore` it has a 2+ charge.
Chlorine is in group 7 `therefore` it has a -1 charge.

As the overall charge is 0 (neutral) the charges must balance. Therefore we need two chlorine ions to balance out the calcium ion charge as `2-2=0`

`therefore` have `CaCl_2`

Note that the 2 is supposed to be little and under the chlorine symbol, i just don't know how to edit it.