which of the following has highest ionization energy a Be b B c N d O
Answers
Explanation:
Boron, B is smaller than beryllium, Be atom. Hence we expect increase in ionization energy from Be to B.
However, Be atom has greater ionization energy than B atom. The reason is - in case of Beryllium, the last electron is in the s-orbital and in Boron, the last electron is in the p-orbital. We know that removal of electron from s-orbital requires more energy than the electron from p-orbital.
* 2s22p3 configuration is more stable than 2s22p4 due to half filled p-sublevel. The electrons in the p-orbital in N atom experience less repulsion, thus more stable and more ionization energy. Whereas in case of O atom the 4th p-electron atom can be removed more easily as it experiences more repulsion from the electrons in the p-orbitals already present. Hence nitrogen, Oxygen atom has less ionization energy than Nitrogen atom.
Conclusion:
The correct ionization energy order is: B < Be < O < N