The UV-visible absorption bands in the spectra of lanthanoid ions are ' $X$ ', probably because of the…
The UV-visible absorption bands in the spectra of lanthanoid ions are ' $X$ ', probably because of the excitation of electrons involving ' $Y$ '. The ' $X$ ' and ' $Y$ ', respectively, are :
Broad and f orbitals
Narrow and f orbitals
Broad and d and f orbitals
Narrow and d and f orbitals
Solution
In lanthanoids, absorption bands are narrow because of excitation within f-level.