Question

which of the following statements is true about ions?
○ anions form when an atom gains protons.
○ anions form when an atom loses protons.
○ cations form when an atom gains electrons.
○ cations form when an atom loses electrons.

Explanation:

• Anions are negatively - charged ions. They form when an atom gains electrons, not protons or loses protons. Protons are in the nucleus and are not easily gained or lost in normal ion - formation processes.
• Cations are positively - charged ions. They form when an atom loses electrons. When an atom gains electrons, it would become negatively charged (an anion), not a cation.

Answer:

Cations form when an atom loses electrons.