Question

The electronic configuration in the outermost shell of halogens is

• A. $s^2{p}^4$
• B. $s^2{p}^5$
• C. $s^2{p}^3$
• D. $s^2{p}^6$

Answer 1

Answer: (B)

All of these halogen have seven electrons in their outer shell.
The electronic configuration of the valence shell in the ground state being
$n{s}^{2}n{p}^5$
${}_{9}F=1s^2,\underbrace{2s^{2}2p^5}$
${}_{17}Cl=1s^2,2s^{2}2p^6,\underbrace{3s^{2}3p^5}$
${}_{35}Br=1s^2,2s^{2}2p^6,3s^{2}3p^{6}3d^{10},\underbrace{4s^{2}4p^5}$
${}_{53}I[Xe]\underbrace{4f^{14}}\underbrace{5d^{10}}\underbrace{6s^{2}6p^5}$