Explanation:
\(4Na_3PO_4\) is a compound which consists of four moles of oxygen, phosphorus and oxygen.
Number of sodium atom in \(4Na_3PO_4\) is, \(4\times 3=12\ atoms\)
Number of phosphorus atom in \(4Na_3PO_4\) is, \(4\times 1=4\ atoms\)
Number of oxygen atom in \(4Na_3PO_4\) is, \(4\times 4=16\ atoms\)
Hence, the no of atoms of each element are as follows :
Sodium, Na = 12 atoms
Phosphorus, P = 4 atoms
Oxygen, O = 16 atoms
Hence, this is the required solution.