Question

a metal M readily forms water soluble sulphate MSO4 ,water insoluble Hydroxide M(OH)2 and oxide MO which becomes inert on heating .The Hydroxide is soluble in NaOH .The metal M is

Answer 1

On moving down, water solubility of alkaline earth metals decreases.

Oxides and hydroxides of alkaline earth metal are basic except Be which is amphoteric.

Hence, the metal is Be.

Answer 2

the the answer is beryllium (be)..

since as we move down the group the solubility decreases...