Which of the following best describes the general trend for electron affinity values as you move from left to right across a period in the periodic table?

• A. Electron affinity remains constant.
• B. Electron affinity first increases, then decreases.
• C. Electron affinity generally increases.
• D. Electron affinity generally decreases.

Answer: (C)

Verified step by step guidance

1. Understand that electron affinity refers to the energy change that occurs when an atom gains an electron, typically releasing energy (exothermic process).
2. Recall that as you move from left to right across a period in the periodic table, the nuclear charge (number of protons) increases while the atomic radius generally decreases.
3. Recognize that a higher nuclear charge with a smaller atomic radius means the nucleus attracts additional electrons more strongly, which tends to increase the electron affinity.
4. Note that there are some exceptions due to electron-electron repulsions in certain subshells, but the overall trend is an increase in electron affinity across a period.
5. Conclude that the general trend for electron affinity values as you move from left to right across a period is that electron affinity generally increases.