1)Why does the size of atoms of halogen family decreases down the group??
2)reactivity of the atoms of halogen family decreases down the group ,why ??
3)why does the atom of halogen family do not react with water and acids??
(a) How does the chemical reactivity of alkali metals vary on going down in group 1 of the periodic table?
(b) How does the chemical reactivity of the halogens vary on going down in group 17 of the periodic table?
Metallic reactivity decreases down the group.