Why does the chloride ion have a -1 charge?

Question

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

Answer 1

The correct answer is:

c. Chlorine atoms gain an electron.

Chlorine atoms have seven electrons in their outermost shell (the valence shell), and they need one more electron to achieve a stable, full outer shell configuration, which is typically a total of eight electrons. When a chlorine atom gains one electron, it becomes a chloride ion (Cl⁻) with a -1 charge.