Which two transition metal ions has same 3d electronic configuration?
(A) \(Mn^{3+}\)
(B) \(Fe^{2+}\)
(C) \(Mn^{2+}\)
(D) \(Fe^{3+}\)
(E) \(Cr^{3+}\)
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is option 3. (C) and (D) only
The electronic configuration of the given compounds are:
(A) \(Mn^{3+}\)
The electronic configuration of \(Mn\) in the ground state is
\(_{25}Mn \longrightarrow _{18}Ar]\text{ }4s^2\text{ }3d^5\)
The electronic configuration of \(Mn\) in \(+3\) oxidation state is
\(Mn^{3+} \longrightarrow _{18}Ar]\text{ }4s^0\text{ }3d^4\)
(B) \(Fe^{2+}\)
The electronic configuration of \(Fe\) in the ground state is
\(_{26}Fe \longrightarrow _{18}Ar]\text{ }4s^2\text{ }3d^6\)
The electronic configuration of \(Fe\) in \(+2\) oxidation state is
\(Fe^{2+} \longrightarrow _{18}Ar]\text{ }4s^0\text{ }3d^6\)
(C) \(Mn^{2+}\)
The electronic configuration of \(Mn\) in the ground state is
\(_{25}Mn \longrightarrow _{18}Ar]\text{ }4s^2\text{ }3d^5\)
The electronic configuration of \(Mn\) in \(+2\) oxidation state is
\(Mn^{2+} \longrightarrow _{18}Ar]\text{ }4s^0\text{ }3d^5\)
(D) \(Fe^{3+}\)
The electronic configuration of \(Fe\) in the ground state is
\(_{26}Fe \longrightarrow _{18}Ar]\text{ }4s^2\text{ }3d^6\)
The electronic configuration of \(Fe\) in \(+3\) oxidation state is
\(Fe^{3+} \longrightarrow _{18}Ar]\text{ }4s^0\text{ }3d^5\)
(E) \(Cr^{3+}\)
The electronic configuration of \(Cr\) in the ground state is
\(_{24}Cr \longrightarrow _{18}Ar]\text{ }4s^1\text{ }3d^5\)
The electronic configuration of \(Cr\) in \(+3\) oxidation state is
\(Cr^{2+} \longrightarrow _{18}Ar]\text{ }4s^0\text{ }3d^3\)
From the above-given configurations, it is clear that both options (C) and (D) have the same \(3d\) configuration. Hence, the correct answer is (3) (C) and (D) only.