Question

What is the molecular formula of sodium phosphate?

Answer 1

`Na_3PO_4`

Explanation:

This is so since sodium is in group `1` so has a valency of `1+` while phosphate is a polyatomic ion of valency `3-` and thus we need `3` sodium atoms for each `1` phosphate ion, hence, `Na_3PO_4`.
Overall nett charge of molecule must be zero.

The ions will be held together by strong ionic bonds and the molecules by strong coulombic forces of attraction.