Write the formula of an oxo-anion of Manganese (Mn) in which it shows the oxidation state equal to its group number.

Write the formula of an oxo-anion of Chromium (Cr) in which it shows the oxidation state equal to its group number.

Assign the reason for the following : Copper (I) ion is not known in aqueous solution.

Explain the following : (i) The enthalpies of atomization of transition metals are quite high. (ii) The transition metals and many of their compounds act as good catalysts.

Explain the following observation : Most of the transition metal ions exhibit characteristic colour in aqueous solution.

How would you account for the following ? Many of the transition elements are known to form interstitial compounds.

When Cu²⁺ ion is treated with KI, a white precipitate is formed. Explain the reaction with the help of chemical equation.