Increase in Rotational Energy and Absorption Spectrum in Microwave Region

Rotational energy is the energy associated with the rotation of a molecule around its axis. When a molecule absorbs electromagnetic radiation, its rotational energy increases. This increase in rotational energy can be observed in the absorption spectrum in the microwave region.

Microwave region

The microwave region is a part of the electromagnetic spectrum that has wavelengths ranging from 1 millimeter to 1 meter and frequencies ranging from 300 MHz to 300 GHz. This region is commonly used for communication, cooking, and spectroscopy.

Absorption spectrum

An absorption spectrum is a graph that shows the wavelengths of electromagnetic radiation absorbed by a substance. It is obtained by passing a beam of electromagnetic radiation through a sample of the substance and measuring the intensity of the transmitted radiation at different wavelengths.

Increase in rotational energy and absorption spectrum in microwave region

When a molecule absorbs electromagnetic radiation in the microwave region, its rotational energy increases. This increase in rotational energy can be observed in the absorption spectrum as a series of sharp peaks or lines. These peaks or lines are known as rotational transitions.

The frequency of the absorbed radiation is directly proportional to the difference in energy between the initial and final rotational states of the molecule. This relationship is described by the equation:

ΔE = hν

where ΔE is the difference in energy, h is Planck's constant, and ν is the frequency of the absorbed radiation.

In conclusion, the increase in rotational energy of a molecule due to absorption of electromagnetic radiation can be observed in the absorption spectrum in the microwave region. This region is commonly used for spectroscopy because many molecules have rotational transitions in this region, making it useful for identifying and studying different types of molecules.