Although it may seem that Fluorine should have the greatest electron affinity, the small size of fluorine generates enough repulsion that Chlorine has the greatest electron affinity.
Meskipun tampaknya Fluor seharusnya memiliki afinitas elektron terbesar, ukuran fluorin yang kecil menghasilkan cukup sangkalan bahwa Klorin memiliki afinitas elektron terbesar.