Question

How do you find the ionic or covalent chemical formulas for molecules?

For example:
Sulfur trioxide
Carbon tetrachloride
Silicon dioxide

Answer 1

How else but by experiment?

Explanation:

We write `SO_3,` `C(Cl)_4,` and `SiO_2` very easily. We forget the experiments that chemist performed 150-200 years ago to establish these compositions and formulae.