Sea divers use a mixture of

The order $H_2O < H_2O_2$ is correct for which of the following properties?

Match the correct option from Column $-A$ and Column $-B.$

Column $-A$	Column $-B$
$(1).$ $H_2O_2$	$(p).$ As moderator
$(2).$ $D_2O$	$(q).$ As fuel
$(3).$ Liquid $H_2$	$(r).$ For to make hard water soft
$(4).$ Zeolite	$(s).$ As disinfectant

Match the items in Column-$I$ with the relevant item in Column-$II$.

Column-$I$	Column-$II$
$A$. Hydrogen peroxide is used as a	$1$. zeolite
$B$. Used in Calgon method	$2$. perhydrol
$C$. Permanent hardness of hard water is removed by	$3$. sodium hexametaphosphate
	$4$. propellant

Fill in the blanks:
$(1)$ Only $..........$ element of group $-6$ forms hydride.
$(2)$ $..........$ is used as a moderator in nuclear reactors.
$(3)$ The three-dimensional arrangement in ice occurs due to $..........$ bonding.
$(4)$ $..........$ method is used to obtain $H_2O_2$ from $2-$ethylanthraquinol.

Match Column-$I$ with Column-$II$ for the given properties/applications mentioned therein.

Column-$I$	Column-$II$
$A$. $H$	$1$. Used in the name of perhydrol.
$B$. $H_2$	$2$. Can be reduced to dihydrogen by $NaH$.
$C$. $H_2O$	$3$. Can be used in hydroformylation of olefin.
$D$. $H_2O_2$	$4$. Can be used in cutting and welding.