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

Assertion : Barium is not required for normal biological function in humans.
Reason : Barium does not show variable oxidation states.

The ion having the highest hydration enthalpy among the given alkaline earth metal ions is:

$A$ metal $M$ readily forms its sulphate $MSO_4$ 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. Then $M$ is

$MgO$ is used for lining furnaces because

Give two uses of Plaster of Paris.