Explain giving reasons: (i) Transition metals and many of their compounds show paramagnetic behaviour. (ii) The enthalpies of atomisation of the transition metals are high. (iii) The transition metals generally form coloured compounds. (iv) Transition metals and their many compounds act as good catalyst.

Explanation

(a) As metal ions generally contain one or more unpaired electrons in them & Hence their complexes are generally paramagnetic.
(b). Because of having larger number of unpaired electrons in their atoms, they have stronger interatomic interaction and hence stronger bonding between the atoms.
(c). May be attributed to the presence of unparied electrons (d-d transition in most of the compounds).