The correct order of the solubility of sulphates of alkaline earth metals is:

$Assertion$ $(A)$: Helium and beryllium have similar outer electronic configuration $ns^2$. $Reason$ $(R)$: Both are chemically inert.

Which of the following elements has two electrons in the $Q$ shell in its ground state?

Which property of alkaline earth metals increases with an increase in atomic number?

Calcium is obtained by which of the following methods?

Fill in the blanks:
$(1)$ Calcium and beryllium have flame colors of ...... and ....... respectively.
$(2)$ Quantitative analysis of calcium is carried out by ........
$(3)$ Beryllium powder on combustion burns brightly in air and gives ...... and .......
$(4)$ Beryllium hydroxide on dissolving in alkali gives .......