Why is the first electron affinity exothermic?
1 Answer
Dec 7, 2015
Sometimes it is; especially for elements to the right of the Periodic Table.
Explanation:
Electron affinity is the enthalpy associated with the reaction:
We would expect this enthalpy to increase across a Period from left to right (because of the increased nuclear charge), and to decrease down a Group, as the nuclear charge is insulated by intervening electron shells.
Metals tend to have low electron affinity, as these are reducing species.
