Question

chlorine forms the chloride ion to bond with many metals. to become a chloride ion with a -1 charge, a chlorine atom must
a gain one proton.
b lose one proton.
c gain one electron.
d lose one electron.

Explanation:

To determine how a chlorine atom becomes a chloride ion (\(Cl^-\)) with a -1 charge, we analyze the subatomic particles involved:

• Protons determine the element (chlorine has 17 protons, and this number doesn’t change to form an ion, so options A and B are incorrect).
• Electrons determine the charge. A neutral atom has equal protons and electrons. A -1 charge means the ion has one more electron than protons. So, a chlorine atom (neutral, 17 electrons) must gain 1 electron to have 18 electrons, resulting in \(Cl^-\). Losing an electron (option D) would give a positive charge, which is incorrect.

Answer:

C. gain one electron.