Which type of element is likely to have a higher electron affinity?

• A. Transition metals in the center of the periodic table
• B. Noble gases in Group 18
• C. Alkali metals in the lower left of the periodic table
• D. Nonmetals in the upper right of the periodic table

Answer: (D)

Verified step by step guidance

1. Understand that electron affinity refers to the energy change when an atom gains an electron, typically indicating how strongly an atom attracts additional electrons.
2. Recall the general periodic trend: electron affinity tends to increase across a period from left to right due to increasing nuclear charge, which attracts electrons more strongly.
3. Recognize that electron affinity generally decreases down a group because added electron shells increase the distance between the nucleus and the added electron, reducing attraction.
4. Analyze the given options: transition metals (center of the table) have moderate electron affinities, noble gases (Group 18) have very low or positive electron affinities because their electron shells are full, and alkali metals (lower left) have low electron affinities as they prefer to lose electrons.
5. Conclude that nonmetals in the upper right of the periodic table (excluding noble gases) have the highest electron affinities because they strongly attract electrons to complete their valence shells.