$A$ metal is burnt in air and the ash on moistening smells of $NH_3$. The metal is

Sorel's cement is

Which property of the alkaline earth metals increases with their atomic number?

Choose the correct statement from the following:
$(i)$ Beryllium is not readily attacked by acids because of the presence of an oxide film on the surface of the metal.
$(ii)$ $BeO$ is an amphoteric oxide.
$(iii)$ Beryllium exhibits coordination number more than four.
$(iv)$ Beryllium oxide is purely acidic in nature.

Slaked lime $[Ca(OH)_2]$ is used in the manufacture of:

$A$ metal $M$ readily forms a water-soluble sulfate $MSO_4$,a water-insoluble hydroxide $M(OH)_2$,and an oxide $MO$ which becomes inert upon heating. The hydroxide is soluble in $NaOH$. What is $M$?