Answer:
2.0*10^24 atoms
Step-by-step explanation:
To find the number of atoms of P in H3PO4, we need to use the Avogadro's number.
The Avogadro's number is 6.022×10^23.
From there, we can set up a "conversion factor tree" to solve for the number of atoms of P:
3 moles P × 6.022×10^23 atoms
------------------------------ = 2.0*10^24 atoms
1 mol
The moles cancel out and you are left with the number of atoms.
Make sure it's the correct number of sig figs.