Question

While converting $Ce$ to $C{e}^{3+}$, which process requires highest ionization energy?

• A. $Ce$ to $C{e}^{+}$
  
• B. $C{e}^{+}$ to $C{e}^{3+}$
  
• C. Both A and B require the same amount of energy.
• D. None of the above

Answer 1

The correct option is B $C{e}^{+}$ to $C{e}^{3+}$


Removing two electrons from $C{e}^{+}$ to convert it to $C{e}^{3+}$ will require much more energy than it would take to remove one electron from $Ce$ to convert it to $C{e}^{+}$. It is easy to remove only the outer most electron but as we move towards nucleus we need more energy to remove the electron from inner orbitals. Hence the energy required to convert $\left(C{e}^{+}\right)$ to $\left(C{e}^{3+}\right)$ is much greater than what would be required for converting $Ce$ to $\left(C{e}^{+}\right)$.