Question

The second electron affinity is always endothermic no matter which element is under consideration. Justify.

Answer 1

Electron affinity: The electron affinity is the amount of energy liberated when an electron is added to a neutral atom to form a negatively charged ion or anion.

• In the first electron affinity, one electron is added to the atom then the atom will become negatively charged.
• Due to the negative charge present in the element after 1st electron affinity, there will be electron-electron repulsion during the addition of the second electron (second electron affinity).
• To counter the repulsion experienced by the electron, energy will be absorbed from the surroundings to add the second electron to the anion. So, the second electron affinity will be endothermic.

Therefore, the second electron affinity of all the elements is always endothermic.