Which of the following units of measurement is used to measure very short wavelengths of light?

Both Angstrom and Millimicron are suitable units of measurement used to quantify very short wavelengths of light. An Angstrom is equivalent to one ten-billionth of a meter (10^-10 meters), making it a useful unit for expressing wavelengths of visible light and other forms of electromagnetic radiation. The millimicron, which is another term for nanometer, equals one-millionth of a millimeter or one billionth of a meter (10^-9 meters).

In the context of light's wavelength, both units are appropriate and commonly used. Visible light wavelengths range typically from about 4000 to 7000 Angstroms, which corresponds to 400 to 700 nanometers. Therefore, using both Angstrom and Millimicron reflects an understanding of the characteristics of light wavelengths in a manner that effectively facilitates their measurement and application in scientific contexts.