Ground State Electron Configuration of Halogen Negative Ions

1. What is the ground state electron configuration of the negative ion of a halogen?

A) 182 282 2p5 382 3p5

B) 182 282 2p6 382 3p6

C) 182 282 2p6 2d10 382 3p6

D) 182 282 2p6 382 3p6 3d5

Answer:

The ground state electron configuration of the negative ion of a halogen is represented by option B) 182 282 2p6 382 3p6.

When a halogen gains an electron to form a negative ion, it achieves a stable octet configuration, similar to the nearest noble gas. The electron configuration of a halogen will have the same configuration as the nearest noble gas, but with one additional electron. For example, chlorine (Cl) has the electron configuration 1s2 2s2 2p6 3s2 3p5 in its ground state. The negative ion of chlorine (Cl-) will gain one more electron, resulting in the electron configuration 1s2 2s2 2p6 3s2 3p6, which matches option B.