how many atoms present in 1ml of NH3 at STP?

So 1 ml has 1/22400 moles at STP.1 mole = 6.022 x 1023 molecules.
So number of molecules of ammonia in 1 ml = 6.022 x 1023/22400.
= 0.027 x 1021
Now, multiply this number by 4 to get the total number of atoms as each molecule of ammonia has 4 atoms ( 1 N and 3 H).
= 4 x 0.027 x 1021
= 0.1075 x 10 21
= 1.075 x 10 20
Therefore, 1ml oh NH3 contains 1.075 x 10²⁰atoms at STP.