Question

why transition metal are coloured​

Answer 1

Answer :-

Because light passes to electrons from a(d) orbital as then go higher from (1) they are filled form (n-1)d orbitals.

Answer 2

Answer:

In transition metals, however, visible light excites the electrons from a lower d orbital to a higher one and only letting some light through. Colored compounds of transition elements are associated with partially filled (n-1)d orbitals. ... The color of ion is complementary of the color absorbed by it.