The metal that gives hydrogen gas upon treatment with both acid as well as base is

$A$ red coloured mixed oxide $(X)$ on treatment with conc. $HNO_3$ gives a compound $(Y).$ $(Y)$ with $HCl$ produces a chloride compound $(Z)$ which can also be produced by treating $(X)$ with conc. $HCl.$ Compounds $(X),$ $(Y),$ and $(Z)$ will be

Which of the following pairs of atomic numbers represents elements belonging to the $s$-block?

Which of the following does not dissolve in dil $H_2SO_4$?

Identify the correct statements from the following:
$I$. $LiF$ is less soluble in water than $NaF$
$II$. Both $LiCl$ and $MgCl_2$ are insoluble in ethanol
$III$. Both $Li$ and $Mg$ form nitrides
$IV$. $Na_2CO_3$ gives $CO_2$ on heating

Match Column-$I$ with Column-$II$ :

Column-$I$	Column-$II$
$(a)$ $NaOH$	$(p)$ Silvine
$(b)$ $Na_2CO_3$	$(q)$ As cooling agent in nuclear reactor
$(c)$ Liquid $Na$	$(r)$ Detergent soap
$(d)$ Potassium	$(s)$ In purification of Bauxite