Question

interpret the number of moles of oxygen atoms in PO3-/4

Answer 1

n=m?M =16?4?16=4

As it is 04 hence there is 4 atoms of Oxygen in PO4

Answer 2

In PO4 there are 4 moles of oxygen O atoms.

We also know that there are 6.02×10^23 atoms in a mole of an element so

1 mole of oxygen atom=6.02×10^23

4 moles of oxygen atoms=4×(6.02×10^23)=2.408×10^24 atoms of oxygen