Question

which of the following electron configurations of outer sublevels is the most stable?
4d³5s³
4d³5s¹
4d⁴5s²
4d²5s⁴

Explanation:

According to the rules of electron configuration stability, half - filled or fully - filled sub - levels are more stable. For the \(d\) sub - level, the maximum number of electrons is \(10\), and for the \(s\) sub - level, it is \(2\).

• \(4d^{3}5s^{3}\): The \(s\) sub - level can only hold a maximum of \(2\) electrons, so this configuration is incorrect.
• \(4d^{3}5s^{1}\): Neither the \(d\) nor the \(s\) sub - level is half - filled or fully - filled.
• \(4d^{4}5s^{2}\): The \(d\) sub - level is not half - filled or fully - filled.
• \(4d^{5}5s^{1}\): The \(d\) sub - level (\(d^{5}\)) is half - filled and the \(s\) sub - level (\(s^{1}\)) is also in a relatively stable state (similar to the concept of half - filled for the \(s\) sub - level in some cases of electron transfer for stability).

Answer:

\(4d^{5}5s^{1}\)