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
$n s^{2}\, n p^{5}$
${ }_{9} F=1 s^{2}, \underbrace{2 s^{2} \,2 p^{5}}$
${ }_{17} C l=1 s^{2}, 2 s^{2}\, 2 p^{6}, \underbrace{3 s^{2} \,3 p^{5}}$
${ }_{35} B r=1 s^{2}, 2 s^{2} \,2 p^{6}, 3 s^{2}\, 3 p^{6}\, 3 d^{10}, \underbrace{4 s^{2} \,4 p^{5}}$
${ }_{53} I[X e] \underbrace{4 f^{14}} \underbrace{5 d^{10}} \underbrace{6 s^{2}\, 6 p^{5}}$