Question

What units of measurement are used to describe wavelengths?

Answer 1

Hint: The units of measurement of wavelength can only be decided if we know what kind of quantity is termed under it. For this purpose we shall first define what a wavelength is and then try to answer our question. A wavelength as the name suggests is the length of one complete wave or oscillation in a moving or standing wave. Using this definition, we shall proceed ahead in our problem.

Complete step-by-step solution:
Since, wavelength is the “length” of one wave, therefore it measures the quantity of length. Now, in the SI unit of measurement, the length of a wave is measured in meters (m).
Now, since wavelengths are associated with all kinds of mechanical and non-mechanical waves, there are other different units of measurement that are frequently used. Wavelength of electromagnetic radiation is always too small to be seen by the naked eye. So, we use terms like micro and nano to make our observations easier and less clumsy. Some of these terms are:
(a) Micron (micrometers): 1 micron is equal to ${{10}^{-6}}m$ and is comparatively larger of the smaller terms that are used.
(b) Nanometer: 1 nanometer is equal to ${{10}^{-9}}m$ and is the most widely used term to depict the wavelength of electromagnetic radiation.
(c) Angstrom: 1 Angstrom is equal to ${{10}^{-10}}m$and it is also very often used in calculations.
Apart from these, there are many other units like Picometer (${{10}^{-12}}m$) and Femtometer(${{10}^{-15}}m$) that are generally used less.

Note: Here, we saw the different terms used to describe wavelength. But it can be clearly noted that all these different terms are finally written in terms of meter as it is the base unit of length. But still, these terms are of great help to describe size and distances when working at the quantum level.