Which element of the \(3 d\)-series has highest third ionisation enthalpy?
Which element of the \(3 d\)-series has highest third ionisation enthalpy?
\(\mathrm{Mn}\)
\(\mathrm{Zn}\)
\(\mathrm{Fe}\)
\(\mathrm{Cu}\)
Solution
The electronic configuration of zinc metal is
\(\mathrm{Zn} \Rightarrow[\mathrm{Ar}] 3 d^{10}, 4 s^2\)
The third ionisation enthalpy of \(\mathrm{Zn}\) means removal of electron from the stable configuration of \(3 d^{10}\).
The metal having the highest third ionisation enthalpy is \(\mathrm{Zn}\). Hence, the correct option is (b).
*