The molecular formula for compound is mass of compound is 0.670 g.
To calculate number of atoms first calculate number of moles in the compound as follows:
Molar mass of is 283.886 g/mol, thus,
Thus, number of mole of is 0.00236 mol.
From the molecular formula 1 mole of has 2 mol of P (phosphorus) and 5 mol of O (oxygen).
Thus, number of moles of P and O in 0.00236 mol of will be:
Similarly,
Now, in 1 mol of an element there are atoms.
Number of atoms of P will be:
Similarly, number of atoms of O will be:
Total number of atoms will be sum of number of atoms of P and O:
Therefore, total number of atoms in will be
.