Electron Affinity Trend
Electron affinity generally becomes more negative (stronger) from left to right across a period, with some exceptions.
Periodic Trend
Highest Values
Cl - Chlorine 3.61
F - Fluorine 3.40
Br - Bromine 3.36
I - Iodine 3.06
At - Astatine 2.80
Lowest Values
He - Helium -19.70
Ar - Argon -11.50
Be - Beryllium -2.40
N - Nitrogen -1.40
Xe - Xenon -0.06