Why does the chloride ion have a -1 charge?

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

c

Chlorine atoms gain an electron.

The correct answer is c. Chlorine atoms gain an electron.

Chlorine is a halogen element with an atomic number of 17. In its neutral state, chlorine has 17 protons and 17 electrons. When a chlorine atom gains one electron, it achieves a stable electron configuration and forms a chloride ion (Cl-).

The electron gained by the chlorine atom fills its outermost energy level, resulting in a complete electron shell with 18 electrons. This extra electron gives the chloride ion a net negative charge of -1.