# Why is the electron affinity for nitrogen positive?

##### 1 Answer
Dec 7, 2015

Since we typically expect electron affinity to be negative except for certain exceptions like Nitrogen, this is one of those exceptions.

Nitrogen's electron configuration is $1 {s}^{2} 2 {s}^{2} 2 {p}^{3}$, so all three $p$ orbitals have one electron each.

Since electron affinity is associated with the "love" for acquiring another electron, and the new electron would be added in one of the singly-occupied $p$ orbitals, we have a problem.

Each singly-occupied $p$ orbital already has one electron, so that electron, clearly identical to the electron being added in every way---INCLUDING CHARGE---will repel the incoming electron, so more energy than usual is needed to add it.

This extra energy needed to overcome the repulsion makes the electron affinity positive.