Question
Tue February 14, 2012 By: Sagar

Why is the ELECTRON AFFINITY for Cl > F ?

Expert Reply
Tue February 14, 2012
Because fluorine is such a small atom, when we add one electron, this new electron goes into a region of space already crowded with electrons and there is a significant amount of repulsion. This repulsion lessens the attraction the incoming electron feels and so lessens the electron affinity. In case of chlorine, due to the availability of vacant d-orbitals the size of atom increases. The coming electron causes less repulsion. So, chlorine has more electron affinity than fluorine. 
Home Work Help