* Anions are negatively charged ions. They form when an atom gains electrons.
Let's analyze each element:
* Ar (Argon): Argon is a noble gas. Noble gases have a full outer shell of electrons, making them very stable. They don't readily gain or lose electrons, so Argon is unlikely to form an anion.
* Cl (Chlorine): Chlorine is a halogen. Halogens have seven electrons in their outer shell. They are highly electronegative (they "want" to gain an electron to achieve a full outer shell). Therefore, Chlorine is very likely to form an anion (Cl⁻).
* Na (Sodium): Sodium is an alkali metal. Alkali metals have one electron in their outer shell. They readily lose this electron to achieve a stable configuration. This means they form cations (positively charged ions), not anions.
* Ne (Neon): Like Argon, Neon is a noble gas. It has a full outer shell of electrons and is extremely stable. It won't readily form an anion.
In summary:
* Cl (Chlorine) is the only element in your list likely to form an anion.
