Why does the chloride ion have a -1 charge?

Question

a
Chlorine atoms share electrons.
b
Chlorine atoms gain an electron.
c
Chlorine atoms lose an electron.
d
Chlorine atoms have no electrons.

Answer 1

The correct answer is:

b Chlorine atoms gain an electron.

Chlorine is a halogen with an atomic number of 17, and it has seven electrons in its outermost shell. To achieve a stable electron configuration (resembling that of the nearest noble gas, argon), chlorine atoms gain one additional electron. This gain of one electron gives chlorine a -1 charge, resulting in the formation of the chloride ion (Cl⁻).