• # question_answer Oxidation number of Os in$\text{Os}{{\text{O}}_{\text{4}}}$ is A)  +4                B)  +8C)  +10                           D)  +18

Let the oxidation number of Os in $\text{Os}{{\text{O}}_{\text{4}}}$be X. $X+(-2)\times 4=0$ $X-8=0$ $X=8.$ Hence, the correct option is [b].