List the elements from most energy being released by gaining an electron to least

Question

F,Kr,Al

Answer 1

This is referred to as the electron affinity of the atom. That is the energy released when an electron is added to a neutral atom to form the anion. Electron affinity increases going from left to right across a period, and increases going up within a group. Thus, the order of highest electron affinity to lowest would be

F > Al > Kr