(i) $ns^2 np^4$ For n = 3 ; outer electronic configuration = $3s^2 3p^4$ ∴ The element will be in 3rd period, 16th group and p-block (Sulphur). (ii) (n – 1) $d^2 ns^2$ For n = 4 ; outer electronic configuration = $3d^2 4s^2$ ∴ The element will be in 4th period, 4th group and d-block (Titanium). (iii) (n – 2) $f^7$ (n – 1) $d^1ns^2$ For n = 6 ; the outer electronic configuration is $4f^7 5d^1 6s^2$. ∴ The element will be in 6th period, 3rd group and f-block (Gadolinium).