Electron affinity trends

[Camryn Marshall 1C]

Is there a trend that shows increasing and decreasing electron affinity on the periodic table? If not how would we be able to calculate the electron affinity?

[HoganFenster2E]

It is not as periodic as atomic radius or ionization energy, but generally electron affinity is higher for the elements in the top right of the periodic table. However there are a few exceptions like how Carbon's electron affinity is higher than nitrogen's.

[Egbert Lin 3B]

Electron affinity increases upward for the groups and from left to right across periods of a periodic table because the electrons added to energy levels become closer to the nucleus, thus a stronger attraction between the nucleus and its electrons.
Electron affinity decreases down the groups and from right to left across the periods on the periodic table because the electrons are placed in a higher energy level far from the nucleus, thus a decrease from its pull.