Which one of the following elements has the highest ionisation energy?

Options

A. `[Ne] 3s^(2)3p^(3)`
B. `[Ne]3s^(2)3p^(2)`
C. `[Ar] 3d^(10),4s^(2) 4 p^(3)`
D. `[Ne] 3s^(2) 3p^(1)`

Answer

A

Explanation

Key Idea Across a period, increasing nuclear charge outweighs the shielding, hence the outermost electrons are held more and more tightly and ionisation energy. increases across a period while as we move down a group increase in shielding outweighs the increasing nuclear charge and the removal of the outermost electron required Jess energy down a group.

Since, ionisation energy increases in a period and decreases in a group, `[Ne] 3s^(2) 3p^(3)` configuration has the highest ionisation energy among the given element.