Question

The wavelength of light fluoresced by molecules is longer than that absorbed because

a. The molecules move faster, which produces a “red shift” in the fluorescence.

b. Some of the absorbed energy causes bonds in the molecule to break, releasing energy, which results in the longer wavelength.

c. Some of the energy absorbed by the molecules is lost to molecular vibrations before the fluorescence is produced, which results in a longer wavelength.

d. The molecules are excited by the absorption and react with solvent molecules, which changes the electronic transition energy and therefore the wavelength.

Answer 1

- Inter System Crossing 13 Vibrational relanation/ 1 fluorseence phosphorascence. Jablonski diagram Here answer will be It can be explained Here we can see the option from the absorption @. Jablonski diagram. occur, so, vo S, v7o. ى 0 (۷ ر Then vibrational relanation occurs, z.es,vlo S, V20 Then flugoscence occurs, s,,V20 so, vyo. So, we can see energy of fluorseance light in less than that of absorbed light. So, wave length of fluroscence light will be larger,

Now, is not so for option related related this is @ Ar to kinetic to kinetic incorrect. to Movement of molecules energy. Fluorscence is energy of a molecule. Now, for option during fluorscence no bond breaking occurs, so this in incorre et for option @ y Excited molecules does not react with solvent. Solvent is chosen in such a way that this does not react with molecules observer for fluroseence. So this is incorrect.