Question

Which element releases the most energy?

Answer 1

1. The amount of energy released when an electron is added to the outermost shell of an atom is called electron affinity.
2. Electron affinity is also called electron gain enthalpy.
3. It is based on the following two factors: the size of an atom, and the number of protons.
4. Electron affinity increases as we move from left to right in the period, and will decrease when moving down the group.
5. Among all the groups present in the periodic table, halogens have high electron gain enthalpy.
6. Halogens are: Fluorine$\left(\mathrm{F}\right)$, Chlorine$\left(\mathrm{Cl}\right)$, Bromine$\left(\mathrm{Br}\right)$, Iodine$\left(\mathrm{I}\right)$, Astatine$\left(\mathrm{At}\right)$.
7. Fluorine and Chlorine are having the highest electron gain.
8. Chlorine is bigger in size compared to Fluorine, and Fluorine faces an extra repulsion from the existing electrons.
9. Therefore, electrons release more amount of energy when they are added to a Chlorine atom.