Oxidation number of Nitrogen in $NH_4NO_3$ is

What is the correct order of decreasing oxidation state of iodine in the following compounds?

The oxidation states of $S$ in peroxodisulphuric acid $(H_{2}S_{2}O_{8})$ and sodium tetrathionate $(Na_{2}S_{4}O_{6})$ are respectively:

In the reaction,$MnO_{4(aq)}^{-} + Br_{(aq)}^{-} \rightarrow MnO_{2(s)} + BrO_{3(aq)}^{-}$,the correct change in oxidation number of the species involved is

What is the oxidation number of $Xe$ in $Ba_2XeO_6$?

The oxidation number of fluorine in $F_2O$ is