What is the oxidation state of $Fe$ in $Fe_3O_4$?

Which of the following is $NOT$ correct for $C_3O_2$?

The oxidation states of sulphur in $S_8$,$S_2F_2$,and $H_2S$ respectively,are:

The oxidation number and the electronic configuration of sulphur in $H_2SO_4$ is

The oxidation state of chlorine in perchloric acid $(HClO_4)$ is:

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