\(\begin{array}{l}
{F^ - }:1{s^2}2{s^2}2{p^6}\\
C{l^ - }:1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}\\
B{r^ - }:1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}3{d^{10}}4{s^2}4{p^6}\\
{I^ - }:1{s^2}2{s^2}2{p^6}3{s^2}3{p^6}3{d^{10}}4{s^2}4{p^6}4{d^{10}}5{s^2}5{p^6}
\end{array}\)
Lần lượt trùng với Ne,Ar,Kr,Xe