Assign reasons for each of the following:
(i) Transition metals generally form coloured compounds.
(ii) Manganese exhibits the highest oxidation state of +7 among the 3d-series of transition elements. 

Explanation

(i) Transition elements generally form coloured compounds on account of d-d transitions. Due to partial absorption of visible light
(ii) Mn shows the highest oxidation state +7. The bonds in such a higher oxidation state are formed by sharing electrons not by the loss of electrons.e.g., Mn shows + 7 oxidation state in `MnO_4^(-)` in which all the bonds are covalent.