Question

When a molecule absorbs IR electromagnetic energy, what are the vibrational modes affected?

Answer 1

Answer:

C. Stretching

D. Bending

Explanation:

The electromagnetic (EM) spectrum extends from the high energy gamma rays to the low energy radio waves. The infra red (IR) region of the EM spectrum falls in the low energy range and extends from 700 nm to nearly 1 mm. Light or photons of different energy react in a different manner with various molecules.

Molecules in general have three degrees of freedom: rotational, vibrational and translation. Rotational motion is induced by microwaves whereas vibrational motion is induced by infra red waves. Specifically, when a molecule absorbs IR electromagnetic energy, the stretching and bending modes are affected.