Question

An atom has electronic configuration $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{3} 4 s^{2}$, you will place it in

• A. fifth group
• B. fifteenth group
• C. second group
• D. third group

Answer 1

Answer: (A)

fifth group

Answer 2

An atom has electronic configuration, $1 s^{2}, 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{3}, 4 s^{2}$ It is a member of d-block elements because the last electron is filled in d-subshell as $3d^3$ and the following electronic configuration is. possible for d-subshell. Group No. $III\, B\, IVB\, VB\, VIB\, VIIB\, VIII\, VIII\, VIII\, IB\, IIB$ $(13)\, (14)\, (15)\, (16)\, (17)\, (18)\, (19)\, (20)\, (21)\, (22)$ $n s^{2}(n-1) s^{2} p^{6}\, d^{1}\, d^{2}\, d^{3}\, d^{4}\, d^{5}\, d^{6}\, d^{7}\, d^{8}\, d^{9}\, d^{10}$ Hence, it is member of fifth group.