Question

I am interested to remove an electron from Ce to convert it to $C{e}^{+}$ and further all the way to $C{e}^{3+}$. Which process requires higher ionization energy?

• A. Ce to $C{e}^{+1}$
• B. $C{e}^{+1}$ to $C{e}^{+3}$
• C. Both A and B require the same amount of energy.
• D. cannot be answered

Answer 1

The correct option is B $C{e}^{+1}$ 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 $\left(C{e}^{+1}\right)$.