Question

The electronic configuration of X and Y are given below:
where p=proton, n=neutron , e-electron. When these two elements combine together to form a compound, give the mass(in grams) of one mole of this compound.

Answer 1

When these elements combine the total neutrons and protons is (3p+4n+8P+8n) = 11p +12n

protons and neutrons approx have same mass so total mass of one molecule is 23 units.

Thus According to mole definition 23 gram of this contains $6.022\times {10}^{23}$ molecules

So one molecule $=23/(6.023\times {10}^{23})gram=3.82\times {10}^{-23}gram$