# absorbance

CEFR C1 · Noun

Source: https://englishreference.com/word/absorbance
Updated: 2026-05-18

## Definition

the amount of light or energy that a material takes in and does not let pass through.

For teachers: the measure of the amount of light or other electromagnetic radiation that is absorbed by a material. Often expressed as a logarithmic ratio of the intensity of incident light to the intensity of transmitted light.

## Examples

- The scientist measured the absorbance of the solution.
- High absorbance indicates that the material is very effective at trapping light or heat energy.
- In spectroscopy, the absorbance of a sample is directly proportional to the concentration of the substance being analyzed, following the Beer-Lambert law.

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