Oxidation, reduction and redox equations

Easy

Which of these chemical species has the correct oxidation state assigned to the specified element?

Chlorine in $NaClO3\text{NaClO}_3$ is $+ 3$

Nitrogen in $N2H4\text{N}_2\text{H}_4$ is $- 2$

Oxygen in $OF2\text{OF}_2$ is $- 2$

Phosphorus in $H3PO3\text{H}_3\text{PO}_3$ is $+ 5$

Oxidation, reduction and redox equations Questions