When a chemical symbol in a chemical formula has no subscript, what does it mean?

1 Answer
Nov 28, 2016

Answer:

That there is only the one such atom in the formula unit.

Explanation:

So we take a common ionic material such as calcium fluoride, #CaF_2#. In one formula unit there is the one #Ca^(2+)# ion, and #2xxF^-# ions.

In one mole of calcium fluoride, there are one mole of #Ca^(2+)# ions, and two moles of #F^-# ions. How many moles of ions (calcium and fluoride) are in one mole of #CaF_2#?