Absorption spectra appear as wide bands rather than lines. Justify.
Answers
Answer:
In UV-Visible spectra Bonds will be in constant vibration, this variation will absorb nearby energies i.e, ΔE , for this reason UV peaks are broader. Spectrum is broaden by spontaneous emission. ... Electronic transition use higher energy whereas Vibrational/Rotational/NMR transitions use lower energy.
Answer:
It is because they will be in constant vibration
Explanation:
In UV-Visible spectra Bonds will be in constant vibration, this variation will absorb nearby energies i.e, ΔE , for this reason UV peaks are broader. Spectrum is broaden by spontaneous emission. ... Electronic transition use higher energy whereas Vibrational/Rotational/NMR transitions use lower energy. Or in simple words, Electronic excitations are usually accompanied by vibrational transitions which are usually not resolved. As a consequence broad bands result. This is pretty much the same situation as if you investigate the infrared spectra of gases. In this case, vibrational excitations are accompanied by rotational transitions. If your spectrometer is not able to resolve the individual bands, also comparably broad bands result. On the other hand, if you have liquids or solids, these rotational transitions are no longer possible and you see solely the band of the vibrational transition.