Given below are two statements: Statement I: The absorption spectra of lanthanoid ions consist of sharp, narrow bands in the UV-visible region. Statement II: The narrow bands are a result of strong interactions between 4f electrons and the surrounding ligand field. In the light of the above statements, choose the most appropriate answer from the options given below:

Step-by-step solution

Statement I is correct because the electronic spectra of lanthanoid ions exhibit sharp, line-like narrow absorption bands primarily due to f-f transitions. Statement II is incorrect. The 4f orbitals in lanthanoids are deeply buried and effectively shielded by the outer 5s and 5p electrons. As a result, the 4f electrons interact very weakly with the surrounding ligand field. This weak interaction and shielding are precisely why the absorption bands remain narrow and sharp, unlike the broad bands seen in transition m