A metal nitride, M3N2 contains 28% of nitrogen. The atomic mass of metal, M is_____.

In the given metal nitride, nitrogen present is 28% that means, the nitride contains 28 g nitrogen and 72 g metal. Moles of metal =72x Moles of nitrogen =2814=2⇒ Molar ratio, M:N=72x:2=3:272x=3∴x = 24