*in the periodic table the position of h2 is ambiguous
*but it is placed at the top of group 1 above the alkali metal. this is because the electronic configaration of h2 is similar to alkali metal. both have valency 1.
*however because of its small size properties of h2 do not match with alkali metal
*sometimes h2 is not included in any group of the periodic table and it is treated as specific elements