To determine which transition metal has the highest third ionization enthalpy, we need to consider the electronic configurations and the stability of the resulting ions upon successive ionizations.
The electronic configuration for each element is as follows:
The third ionization enthalpy refers to the energy required to remove the third electron after removing the first two. When evaluating this, the stability of half-filled d-orbitals plays a significant role.
For manganese (Mn), removing the first two electrons results in a configuration of \(3d^5\), which is a stable half-filled configuration.
This stability makes it significantly more challenging to remove a third electron from manganese than from the other elements.
Therefore, the element with the highest third ionization enthalpy is: Mn (Manganese).
The 3rd ionisation enthalpy refers to the energy required to remove the third electron after the removal of the first and second electrons from a neutral atom.
Reasoning for Mn Having the Highest 3rd Ionisation Enthalpy
Manganese (Mn) has the electronic configuration [Ar] $3d^5 4s^2$.
The removal of the first and second electrons leads to a half-filled $3d^5$ configuration, which is highly stable due to symmetrical distribution and exchange energy.
Removing the third electron from this stable half-filled $3d^5$ configuration requires a significantly higher amount of energy compared to other transition elements such as Cr, V, and Fe.
Conclusion: The transition metal having the highest 3rd ionisation enthalpy is Mn.
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)

Cobalt chloride when dissolved in water forms pink colored complex $X$ which has octahedral geometry. This solution on treating with cone $HCl$ forms deep blue complex, $\underline{Y}$ which has a $\underline{Z}$ geometry $X, Y$ and $Z$, respectively, are
What will be the equilibrium constant of the given reaction carried out in a \(5 \,L\) vessel and having equilibrium amounts of \(A_2\) and \(A\) as \(0.5\) mole and \(2 \times 10^{-6}\) mole respectively?
The reaction : \(A_2 \rightleftharpoons 2A\)
A black body is at a temperature of 2880 K. The energy of radiation emitted by this body with wavelength between 499 nm and 500 nm is U1, between 999 nm and 1000 nm is U2 and between 1499 nm and 1500 nm is U3. The Wien's constant, b = 2.88×106 nm-K. Then,