4 mol NH₃ → 5 mol N₂
x mol NH₃ → 0.824 mol N₂
x=0.824*4/5=0.6592 mol
6.02 times 10 to the 23 power, which is Avogadros number
Each shell can contain only a fixed number of electrons: The first shell
can hold up to two electrons, the second shell can hold up to eight (2 +
6) electrons, the third shell can hold up to18 (2 + 6 + 10) and so on.
The general formula is that the nth shell can in principle hold up to
2(n2) electrons.