Question

1

Answer 1

Answer:

1$s^{2}$2$s^{2}$2$p^{6}$3$s^{2}$3$p^{6}$3$d^{10}$4$s^{2}$4$p^{6}$ (alternatively 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6)

Explanation:

The correct configuration for bromide ($Br^{-}$) is:

1$s^{2}$2$s^{2}$2$p^{6}$3$s^{2}$3$p^{6}$3$d^{10}$4$s^{2}$4$p^{6}$ (it has one more electron in 4p orbital than bromine)

You can also write it as [Ar] $4s^{2}$ $3d^{10}$ $4p^{6}$, since noble gases are very stable

First can't be correct because there is nothing in 3p orbital and 4p has only 5 electrons here

1s² 2s2 2p6 3s2 3p 4s2 3d10 4p5

Second can't be correct because there is nothing in 2p and 4p orbitales 1s2 2s² 2p 3s2 3p6 4s2 3d10 4p

Third can't be correct because there is nothing in 3p orbital and 4p has only 5 electrons here

1s 2s2 2p6 3s2 3p' 4s2 3d10 4p5

Fourth can't be correct because there is nothing in 2p and 3d orbitales, and 4p has only 5 electrons here

1s2 2s2 2p 3s2 3p6 4s2 3dº 4p5