Elements a, b, c, d and e have the following electronic configuration
(a) `1s^(2)2s^(2)2p^(1)` (b) `1s^(2)2s^(2)2p^(6)3s^(2)3p^(1)` (c) `1s^(2)2s^(2)2p^(6)3s^(2)3p^(3)` (d) `1s^(2)2s^(2)2p^(6)3s^(2)3p^(5)` (e) `1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(2)`
Which among these will belong to the same group in the periodic table ? a & d, b&c, a & b, a & e

Options

A. a&d
B. b&c
C. a&b
D. a&e

Answer

C

Explanation

Similar valence `e^- , 2s^2 2p^1` and `3s^2 , 3p^1`