Why some complexes of d-block elements are colorless i.e. white?

Ans. In some complexes, the metal ion has no electrons in the d-orbitals (d0 configuration). Thus, when the visible light spectrum(white light) passes through the solution, there are no electrons to absorb the wavelength of the light. hence, all the seven rays of white light are transmitted giving white colour which means the complex is … Read more

Why many compounds (or complexes) of d-block elements are coloured?

Ans.  D-block elements have electrons in the d-orbital. The d-orbitals split into two groups,t2g(lower energy) and eg(higher energy) in an octahedral complex. When white light falls in the complex compound, the electron of t2g orbital absorbs a certain wavelength from the white light(VIBGYOR) and moves to eg orbital. The remaining part of the light is … Read more