In $H_2O_2$,the two oxygen atoms are connected by:

The reaction $H_2S + H_2O_2 \to S + 2H_2O$ manifests:

The chemical nature of hydrogen peroxide is

$H_2O_2$ is a

Peroxide bond is present in

Fill in the blanks:
$(1)$ $H_2O_2$ acts as an antiseptic, then it is known as ......... in the market.
$(2)$ Cation exchange resin is a ......... group containing organic molecule.
$(3)$ The ionic radius of $H^+$ ions and that of other ions is ......... $pm$ and ......... $pm$ respectively.
$(4)$ ......... group elements give salt-like hydrides.