- molar extinction coefficient (also called molar absorptivity) are parameters defining how strongly a substance absorbs light at a given wavelength, per mass density or per molar concentration, respectively.
- Molar absorptivity, also known as the molar extinction coefficient, is a measure of how well a chemical species absorbs a given wavelength of light. It allows you to make comparisons between compounds without taking into account differences in concentration or solution length during measurements.