Question

Which of the following can result in decreased electron affinity?

A) Decreased atomic size.
B) Increased atomic size.
C) Increased effective nuclear charge.
D) None of the above.

Answer 1

Decreased electron affinity can result from an increased atomic size, due to reduced attraction between the nucleus and additional electrons as well as increased electron shielding.

Step-by-step explanation:

Which of the following can result in decreased electron affinity? The correct answer is B) Increased atomic size. Electron affinity generally decreases as atomic size increases. This is because as the atomic radius becomes larger, the outer electrons are further from the nucleus, thus the attractive force on additional electrons is weaker. Additionally, there is more shielding of the nucleus by the inner electrons which can reduce the electron-nucleus attraction. Thus, when atomic size increases, it is energetically less favorable for an atom to gain an electron, leading to a decrease in electron affinity.