Question

Why is iodine less reactive than bromine?

Answer 1

Reactivity of non-metals:

• Down the group reactivity decreases in the case of non-metals.
• This is because down the group size increases and the tendency to pull electrons towards the nucleus decreases. As a result electronegativity decreases and then reactivity also decreases.

Reason for less reactive Iodine.

• Iodine contains five shells, whereas Bromine has four.
• Because bromine has fewer shells, the outer shell is closer to the nucleus, and there is a significant interaction between the nucleus's positive charge and the electrons in the outermost shell, when contrasted to iodine, this makes it easier for bromine to acquire an electron to the outer shell.
• Bromine is thus more reactive than iodine.