Alkaline earth metals belong to the

Plaster of Paris when mixed with the correct amount of water sets into a solid mass due to the formation of

Assertion $A$: Barium is not required in the normal biochemical processes of the human body.
Reason $R$: Barium does not exhibit more than one oxidation state.

Give the uses of alkaline earth metals.

$CO_2$ is passed through lime water. Initially,the solution turns milky and then becomes clear upon continued bubbling of $CO_2$. The clear solution is due to the formation of:

Alkaline earth metals (except $Be$) can easily lose their valence electrons. Therefore,how do they behave?