Which of the following compounds does not show amphoteric behaviour?

$Ba$,$Ca$,and $Sr$ form halide hydrates. Their formulas are $BaCl_2 \cdot x H_2 O$,$CaCl_2 \cdot y H_2 O$,and $SrCl_2 \cdot z H_2 O$. The values of $x$,$y$,and $z$ respectively are:

What are methanides?

Statement $A$: Helium and Beryllium have the same outer electronic configuration of the type $ns^2$.
Reason $R$: Both are chemically inert.

Among the alkaline earth metals,the element forming predominantly covalent compounds is:

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