Which of the following compounds does not react with cold and dil. $HNO_3$?

Which pair of compounds contains both metals in their highest possible oxidation state?

How are transition metals and their oxides used in industrial processes?

Given below are two statements for catalytic properties of transition metals. Statement $I$: First row transition metals which act as catalyst utilise their $3d$ electrons only for formation of bonds between reactant molecules and atoms on the surface of catalyst. Statement $II$: There is increase in the concentration of reactants on the surface of catalyst which strengthens the bonds in reacting molecules. In the light of the above statements, choose the correct answer from the options given below:

When $KI$ and $CuSO_4$ solutions are mixed,the products formed are:

Addition of high proportions of manganese makes steel useful in making rails of railroads,because manganese