When the oxidation number of an element is maximum, it can act only as . (Reducing agent/Oxidizing agent)

The compound in which oxidation number of oxygen is $+2$ is _____.

$\left(\mathrm{A}\right) {\mathrm{OF}}_2/\left(\mathrm{B}\right) {\mathrm{O}}_2{\mathrm{F}}_2$.

Enter your correct answer as A or B.

In an electrochemical cell consisting of zinc electrode and normal hydrogen electrode, zinc electrode acts as _____.

Salt bridge maintains electrical _____ in the solutions of two half-cells.

Explain the terms oxidation and reduction in terms of electrons. Give one example in each case.