Hey!
The formula mass of ammonia is 14 + 1 3 = 17.
The number of moles in 36 g ammonia is 36/ 17 = 2.11mol.
A mole is 6.02 10, so the number of hydrogen atoms in a 2.11 moles of ammonia is 2.11 *6.02*10^23 = 1.27 *10^24  atoms .
Hope it helps!

Hi Aspirant,

The formula mass of ammonia is 14 + 1 × 3 = 17.

The number of moles in 27.6g ammonia is 27.6 ÷ 17 = 1.62 mol.

A mole is 6.02 × 10²³, so the number of hydrogen atoms in a 1.62 moles of ammonia is 1.62 × 6.02 × 10²³ × 3 = 2.93 × 10² atoms.

I hope it helps you.