Question

which electron configuration of the 4f energy sublevel is the most stable?

o 4f7

o 4f14

o 4f13

o 4f

Explanation:

According to Hund's rule, half - filled (\(n = 7\)) and completely - filled (\(n=14\)) sub - shells are more stable. Among the given options, \(4f^{7}\) is half - filled and \(4f^{14}\) is completely - filled. But when we consider the general trends in electron configurations for the \(4f\) sub - level, the half - filled (\(4f^{7}\)) and completely - filled (\(4f^{14}\)) configurations are stable. However, in the context of lanthanide series and the stability of \(4f\) configurations, the completely - filled \(4f^{14}\) is also a very stable configuration. But if we assume a comparison between the given options, the completely - filled \(4f^{14}\) has all the orbitals in the \(4f\) sub - level filled, which gives maximum stability due to symmetry and minimized electron - electron repulsions.

Answer:

\(4f^{14}\)