Sorel's cement is:

Given below are two statements:
Statement $I$: None of the alkaline earth metal hydroxides dissolve in alkali.
Statement $II$: Solubility of alkaline earth metal hydroxides in water increases down the group.
In the light of the above statements,choose the most appropriate answer from the options given below:

$MgO$ is used as a refractory material because

Both $Be$ and $Al$ become passive on reaction with conc. nitric acid due to :

What is dead burnt plaster?

The alkaline earth metals $Ba$,$Sr$,$Ca$ and $Mg$ may be arranged in the order of their decreasing first ionisation potential as