$A$ white solid '$A$' on heating gives off a gas which turns lime water milky. The residue is yellow when hot but turns white on cooling. This solid '$A$' is

$A$ solid compound $X$ on heating gives $CO_2$ gas and a residue. The residue mixed with water forms $Y$. On passing an excess of $CO_2$ through $Y$ in water,a clear solution $Z$ is obtained. On boiling $Z$,compound $X$ is reformed. The compound $X$ is

Out of $BeF_{2}, MgF_{2}, CaF_{2}, SrF_{2}$,which has maximum solubility?

Give the preparation,properties,and uses of calcium oxide or quick lime $(CaO)$.

$A$ chloride is significantly soluble in cold water. When placed on a $Pt$ wire and heated in a Bunsen flame,it does not impart any characteristic color to the flame. Which of the following cations is present?

Alkaline earth metals are denser than alkali metals because metallic bonding is: