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Definition

noun

(spectrophotometry) A measure of how strongly a chemical species absorbs light at a particular wavelength. It is often expressed in units of cm^-1M^-1.

Supplement

It is symbolized by ε in Beer-Lambert law, A = εcl, where A is the absorbance of the sample, l is the pathlength (usually in centimeter), and c is the concentration of the of absorbing species in the material (moles per liter).

Synonyms:

• molar absorptivity
• molar extinction coefficient

See also: Beer-Lambert law