Which type of atoms is most likely to have the most negative electron affinity?

• A. Transition metals
• B. Alkali metals
• C. Noble gases
• D. Halogens

Answer: (D)

Verified step by step guidance

1. Understand what electron affinity means: it is the amount of energy released when an atom gains an electron, so a more negative electron affinity indicates a stronger tendency to accept an electron.
2. Recall the general trends in the periodic table: electron affinity tends to become more negative across a period from left to right, because atoms have more protons attracting the added electron.
3. Consider the groups given: Transition metals have partially filled d orbitals and generally less negative electron affinities; Alkali metals have a single electron in their outer shell and tend to lose electrons rather than gain; Noble gases have full outer shells and usually have positive or near zero electron affinities because they are stable.
4. Halogens, which are one group before the noble gases, have seven valence electrons and strongly tend to gain one electron to complete their octet, resulting in highly negative electron affinities.
5. Therefore, by comparing these characteristics, halogens are most likely to have the most negative electron affinity among the options given.