Which among the following elements is used in nuclear reactors as a moderator?

Give a detailed explanation of the oxoacid salts of alkaline earth metal elements.

The compound formed when gypsum is dissolved in aqueous ammonium sulphate solution is:

$Beryllium$ and $magnesium$ do not give colour to flame whereas other alkaline earth metals do so. Why?

Which element among the alkaline earth metals primarily forms covalent compounds?

$BeO$ reacts with $HF$ in the presence of ammonia to give $[A]$,which on thermal decomposition produces $[B]$ and ammonium fluoride. The oxidation state of $Be$ in $[A]$ is $.....$.