Question

An element has the electronic configuration
$1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{8}4s^2$.
What will be its position in the periodic table?

• A. Period 4, Group 10
• B. Period 2, Group 2
• C. Period 4, Group 2
• D. Period 2, Group 8

Answer 1

Answer: (A)

Period 4, Group 10

$n=4$ hence, element lies in 4th period,
Group number $=$ number of electrons in ns subshell $+$ number of electrons in (n - 1)d subshell $=2+8=10$.