Consider the following three compounds `(i)AX_(2n)^(n-)`, (ii)`AX_(3n)` and (ii)`AX_(4n)^(n+)`, where central atom A is 15th group element and their maximum covalency is 3n. If total number of proton in surrounding atom X is n and value of n is one, then calculate value of `x^(3)+y^(2)+z^(2)` . (where x, y and z are total number of lone pair at central atom in compounds (i), (ii) and (iii) respectively.

Answer

`9`

Explanation

n=1, then X=H: A=N
(i)`NH_(2)^(-)` (ii)`NH_(3)` (iii)`NH_(4)^(+)`
lone pair x=2, y=1, z=0
`x^(3)+y^(2)+z=2^(3)+1^(2)+0=9