Electron Affinity is the change in energy that occurs when an electron is added to a neutral atom in the gaseous state to form a negative ion.

Explanation:

* Nitrogen (N) has a smaller atomic radius than phosphorus (P). This means that the outermost electrons in nitrogen are closer to the nucleus and experience a stronger attraction.

* The smaller size and stronger nuclear attraction in nitrogen make it easier to add an electron, resulting in a more negative electron affinity value.

Trend in Electron Affinity:

Electron affinity generally increases across a period from left to right and decreases down a group. This is because the nuclear charge increases across a period, making it more attractive to add an electron. However, down a group, the atomic radius increases, reducing the attraction between the nucleus and the added electron.

Therefore, nitrogen, being in the same period but to the left of phosphorus, has a higher electron affinity.