A metal (M) and a non - metal (X) form a compound with formula `M_(4)X_(3)` . Predict the electronic arrangements of M and X assuming that M has three occupied shells and X has two occupied shells. Also derive the formulae of (a) sulphate (b) dihydrogen phosphate ( c) hydroxide of ion of M.

Explanation

Formula `M_(4)X_(3)` corresponds to `M^(+3)X^(-4)`. M has three occupied shells K, L and M . The number of electrons in valece shell is equal to 3. the electronic arrangement could be 2 , 8 , 3 which corresponds to Z = 13 that is aluminium . X has two occupied shells K and L and L shell must have 4 electrons . the electronic arrangement could be 2 , 4 which corresponds to Z = 6 that is carbon.
(a) `{:(Al^(+3)SO_(4)^(-2),),(Al_(2)(SO_(4))_(3),):}`
(b) `{:(Al^(+3)H_(2)PO_(4)^(-),),(Al(H_(2)PO_(4))_(3),):}`
(c ) `{:( Al^(+3)OH^(-),),(Al(OH)_(3),):}`