The presence of $Mn$ in steel produces

Name the oxometal anions of the first series of the transition metals in which the metal exhibits the oxidation state equal to its group number.

When a mixture of $NaCl$,$K_{2}Cr_{2}O_{7}$ and conc. $H_{2}SO_{4}$ is heated in a dry test tube,a red vapour $(X)$ is evolved. This vapour $(X)$ turns an aqueous solution of $NaOH$ yellow due to the formation of $Y$. $X$ and $Y$,respectively,are

The amphoteric oxide among $V_2O_3$,$V_2O_4$,and $V_2O_5$ upon reaction with alkali leads to the formation of an oxide anion. The oxidation state of $V$ in the oxide anion is:

$MnO^{-}_4$ is of intense pink colour,though $Mn$ is in $(+7)$ oxidation state,it is due to

Identify $(A)$,$(B)$ and $(C)$ in the given reaction sequence: