Question

Among the elements H, F, Cl, Br which is likely to have minimum ionization energy and why?

Answer 1

1. Ionisation energy is the energy required to remove the least tightly bound electron of an atom in the gaseous phase.
2. In a periodic table, the ionisation energy increases as we move from left to right in a period and decreases from top to bottom in a group because the atomic radius increases and the outermost electron is less tightly bound to the nucleus.
3. The ionisation energy is inversely proportional to the atomic radius.
4. From the above-mentioned element, Bromine (Br) has the largest atomic radius. So there will be a weak force of attraction between the nucleus and the outermost electron.
5. The ionization energy required to remove the loosely bound electron will be less.
6. Thus, among H, F, Cl, Br, Bromine has the minimum ionization energy.