What is the oxidation state of $S$ in $SO_4^{2-}$?

From the given list,the number of compounds with $+4$ oxidation state of Sulphur is $ . . . . . . $.
$SO_3, H_2SO_3, SOCl_2, SF_4, BaSO_4, H_2S_2O_7$

What are the oxidation states of the two sulfur atoms in thiosulfuric acid $(H_2S_2O_3)$?

Which is $NOT$ correct regarding stock notation?

What is the oxidation state of iodine in $I_2Cl_6$?

Match the items in Column-$I$ with relevant items in Column-$II$.

Column-$I$	Column-$II$
$A$. Positively charged ion	$1$. $+7$
$B$. Oxidation number of all neutral atoms	$2$. $-1$
$C$. Oxidation number of hydrogen $(H^+)$	$3$. $+1$
$D$. Oxidation number of fluorine in $NaF$	$4$. $0$
$E$. Negatively charged ion	$5$. Cation
	$6$. Anion