Why is there a decrease in electron affinity going from lithium to sodium?

A. There is a stronger nuclear charge, with no additional shielding electrons or number of shells.
B. There are fewer spaces in the valence shell in which to place the added electron.
C. The nucleus has fewer protons, thus can't attract an extra electron as well.
D. Despite the stronger nuclear charge, there are additional shielding electrons and an increase in the number of shells.
E. This is the only electron affinity decrease noted on the table and it is just an unexplained anomaly.

I have no idea what the correct answer is . I don't think it is b or d

3 answers

I think the answer could be a. What do you think?
I don't think it's A. A says there are no additional number of shells but Na has another shell not present in Li. Also there ARE additional shielding electrons. Right? I agree that b doesn't sound right. I would bet on D by the process of elimination. A, B, C, E are not true. Ergo, I pick D. I don't believe anything in D is untrue.
Lol! the answer is d guys, coz the 1s 2s and 2p electrons contribute to the shielding effect in na whereas in li its only the 1s electrons contribute to shielding. 100% the answer is d 👍