Which element would most likely have an electron affinity measuring closest to zero?

• A. Ne
• B. Cl
• C. O
• D. Na

Answer: (A)

Verified step by step guidance

1. Understand that electron affinity is the energy change when an atom gains an electron. Elements with nearly full outer shells tend to have electron affinities close to zero because they are stable and do not easily gain electrons.
2. Recall that noble gases, like Neon (Ne), have full valence shells, making them very stable and unlikely to gain electrons, so their electron affinity values are typically close to zero or even positive.
3. Compare the given elements: Chlorine (Cl) and Oxygen (O) are nonmetals that tend to gain electrons easily, so they have relatively high (more negative) electron affinities.
4. Sodium (Na) is an alkali metal with one electron in its outer shell, which it tends to lose rather than gain, so its electron affinity is low but not as close to zero as Neon.
5. Conclude that Neon (Ne), being a noble gas with a full valence shell, would have an electron affinity closest to zero among the options.