Q.
A metal M readily forms its sulphate MSO4 which is water soluble. It forms its oxide MO which becomes inert on heating. It forms its insoluble hydroxide M(OH)2 which is soluble in NaOH solution. What would be M ?
In the periodic table, on moving down, water solubility of alkaline earth metal decreases. Oxides and hydroxides of alkaline earth metal are basic except Be which is amphoteric.