Question

observe the modern periodic table and explain the gradation in rectivity of halogen family

Answer 1

The group 17 contains the members of the halogen family.

All of them have the general formula X2. A gradation is observed in their physical state down the group.

Thus, fluorine (F2) and chlorine (Cl2) are gases. Bromine (Br2) is a liquid while iodine (I2) is a solid.

Answer 2

As we go down the group, the electron affinity of the element decreases. So the reactivity decreases as we go down the group. So fluorine is the most reactive among the halogens.