Listed below are the electronic configuration of five elements. Arrange the elements in the increasing order of metallic character:

(a) $\left[Ar\right]3d^{10}4s^2$

(b) $\left[Ar\right]4s^2$
(c) $\left[Ar\right]3d^{10}4s^{2}4p^{6}5s^2$

(d) $\left[Ar\right]3d^{10}4s^{2}4p^5$
(e) $\left[Ar\right]3d^{10}4s^{2}4p^{6}5s^1$

Five elements A, B, C, D and E have atomic numbers of 2, 3, 7, 10 and 18 respectively. The elements which belong to the same period of the periodic table are :

(a) A, B, C (b) B,C,D (c) A, D, E (d) B, D, E

Electronic configuration of four elements A, B, C, and D are given below
A. $1s^{2}2s^{2}2p^6$ B. $1s^{2}2s^{2}2p^4$ C. $1s^{2}2s^{2}2p^{6}3s^1$
D. $1s^{2}2s^{2}2p^5$
Whilch of the following is the correct order of increasing tendency to gain electron?
(a) A < C <B <D (b) A < B < C < D (c) D <B < C < A (d) D < A < B <C