Question

Amongst the following elements whose electronic configurations are given below, the one having the highest ionisation enthalpy is ______.

Options

• \[\ce{[Ne]}\]3s²3p¹

• \[\ce{[Ne]}\]3s²3p³

• \[\ce{[Ne]}\]3s²3p²

• \[\ce{Ar}\]3d¹⁰4s²4p³ 

Answer 1

Amongst the following elements whose electronic configurations are given below, the one having the highest ionisation enthalpy is \[\ce{[Ne]}\]3s²3p³.

Explanation:

Aluminium has \[\ce{[Ne]}\]3s²3p¹ electronic configuration. Phosphorus has \[\ce{[Ne]}\]3s²3p³ . The electronic configuration of silicon is \[\ce{[Ne]}\]3s²3p²  and the electronic configuration of arsenic is \[\ce{Ar}\]3d¹⁰4s²4p³ .

Ionisation energy increases as the atomic number in a period increases and decreases on moving down the group. It is also known that the ionisation enthalpy of group 15 elements is more than group 16 elements as group 15 has half-filled p-subshells which gives extra stability.