[boodyx1]

steric hindrance(in organic molecule) affect absorptivity,absorbance and intensity of (u.v-v.light) spectra.explain? (please in details)

[cpncoop]

When a molecule absorbs light, it takes a bonding electron and excites it to either a non-bonding orbital.  This changes the bond length, and the molecule vibrates or emits light to return to it's ground state.  If a molecule is severely hindered (in terms of geometry or sterics), transitions can be shifted to higher energies, as the conformational changes required to achieve a stable excited state have a greater energy barrier.

[boodyx1]

thank you