Which of the following gives $H_2O_2$ on hydrolysis?

By which of the following methods,$H_2O_2$ cannot be synthesized?

Hydrogen peroxide $(H_2O_2)$ can be used as:

Select the correct statement.

Which of the following is a true structure of $H_2O_2$?

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.