Question

Amongst the following elements (whose electronic configurations are given below), the one having the highest ionization energy is 

1. [Ne]3s² 3p¹
2. [Ne]3s² 3p³
3. [Ne] 3s² 3p²
4. [Ar] 3d¹⁰ 4s² 4p³

Answer 1

Correct Answer - Option 2 : [Ne]3s² 3p³

Concept:

• Electronic configuration, also called electronic structure, the arrangement of electrons in energy levels around an atomic nucleus.
• In terms of a more refined, quantum-mechanical model, the K–Q shells are subdivided into a set of orbitals (see orbital), each of which can be occupied by no more than a pair of electrons.
• Ionization energy, also called ionization potential, in chemistry and physics, the amount of energy required to remove an electron from an isolated atom or molecule.

Explanation:

• It is considered a measure of the tendency of an atom or ion to surrender an electron or the strength of the electron binding.
• The greater the ionization energy, the more difficult it is to remove an electron.
• The ionization energy may be an indicator of the reactivity of an element.

According to Hund's rule, half-filled and full filled orbitals are more stable. Therefore it is difficult to remove the electron from the half-filled p-subshell.

On moving down the group, the force of attraction between electrons and the nucleus decreases. Hence, Ionisation energy decreases on moving down the group.

So, [Ne]3s2 3p3 has the highest ionization energy in the given options.