The oxidation number of carbon in $CH_2Cl_2$ is

The oxidation number of sulphur in $H_2S$ is

What is the correct order of oxidation states of sulfur in the following anions: $SO_3^{2-}$,$S_2O_4^{2-}$,and $S_2O_6^{2-}$?

Assign the oxidation number to the underlined element in each of the following species:
$1$. $K_2\underline{Mn}O_4$
$2$. $Ca\underline{O}_2$
$3$. $Na\underline{B}H_4$
$4$. $KAl(\underline{S}O_4)_2 \cdot 12H_2O$

Which of the following has been arranged in order of increasing oxidation number of nitrogen?

The oxidation state of nitrogen is incorrectly given for:
Compound $\to$ Oxidation state