Question

Flourine has electron affinity less than that of chlourine why?
Confussion is if electrons in flourine are tightly packed means it has high density then when electron is added in it its remainig electron should repel it so more energy will b release then why its electeon affinity is low?

Answer 1

It is not about how much energy is released. Electron affinity is about how much the atom wants the electron(i.e. in a very generalised way), since fluorine has only the p subshell, therefore it is quite small as compared to fluorine and there is less space between electrons

Answer 2

Answer:

Fluorine, which is higher up the group then chlorine, has a lower electron affinity. This is because the electrons in the outermost shell of a fluorine atom are closer together. ... Energy is required to keep the gained electron in the shell, causing fluorine to have a smaller electron affinity than chlorine.

Explanation: