Which of the following Statement(s) is//are correct?

Options

A. `Transition metals and many of their compounds show paramagnetic behaviour.
B. The enthalpies of atomisation of the transition metals are high
C. The transition metals generally form coloured compounds
D. Transition metals and their many compounds act as good catalyst.

Explanation

As metal ions generally contain one or more unpaired electrons in them & hence their complexes are generally paramagnetic ltbrlt (B) Because of having larger number of unpaired electrons in their atoms, they have stronger inter atomic interaction and hence stronger bonding between the atoms.
(C ) According to `CFT`, in presence of ligands the colour of the compounds is due to the d-d transition of the electrons.
(D) This activity is ascribed to their ability to adopt multiple oxidation state and to form complexes.
Therefore (A,B,C,D)` option are correct.