Question

Rank the nonmetals in each set from most reactive (1) to least reactive (3). Bromine: Chlorine: Iodine:

Answer 1

The most reactive element of this list is Chlorine, the next most reactive is bromine, and the least reactive is iodine.

All of these three elements are group 7 elements in the periodic table. It is known that the reactivity of group 7 elements decreases down the group. The most reactive element in this group is Flourine  with reactivity decreasing down the group.

The reason for this decrease in reactivity is that as you go down the group, the distance between the positive nucleus that attracts valence electrons increases, decreasing the electrostatic attraction between the nucleus and the outer electrons. The other reason is that the electrons in lower energy levels closer to the nucleus repel and shield the electrons in the outermost shell or energy level of the atom.

Chlorine>Bromine>Iodine.

Answer 2

Answer: The order of reactivity of non-metals from most reactive to least reactive is $\text{Chlorine}>\text{Bromine}>\text{Iodine}$

Explanation:

Reactivity of a non-metal is defined as the tendency of an element to gain electrons. The reactivity increases as we move across a period and it  decreases as we move down the group.

When the size of an element increases, the valence electrons gets away from the nucleus and the tendency of an element to gain electrons decreases.

In a group, the size of an element increases because there is an addition of new shell and electron is added in that shell.

The given elements belong to the same group which is Group 17.

Chlorine has the smallest size, then bromine and then iodine.

Hence, the order of reactivity of non-metals from most reactive to least reactive is $\text{Chlorine}>\text{Bromine}>\text{Iodine}$