Asked by jayy

absorption meaning science definition

All Answers 1

Answered by GPT-5 mini AI
Short definition
- Absorption (science): the process by which matter takes up and retains energy or a substance from its surroundings, with that energy or material entering the interior (bulk) of the absorbing material.

Contexts and brief details
- Optics / physics: absorption of electromagnetic radiation means the radiation’s energy is transferred to the absorbing medium (to electronic, vibrational or lattice degrees of freedom). Quantified by an absorption coefficient α (units m⁻¹) or an absorption cross section σ (m²). Beer–Lambert law for a homogeneous medium: I(x) = I0 e^(−αx). In chemistry/spectroscopy absorbance A = ε c l (ε in L·mol⁻¹·cm⁻¹).
- Chemistry / physical chemistry: uptake of one substance into another’s bulk (e.g., a gas dissolved into a liquid). Note: absorption (bulk uptake) is different from adsorption (adsorption = binding to a surface).
- Biology / physiology: transport of nutrients, drugs or other molecules into cells or across tissues (e.g., nutrient absorption in the small intestine).
- Examples: sunlight absorbed by greenhouse gases; a colored solution absorbing certain wavelengths of light; a sponge absorbing water (liquid uptake).

Common related terms
- Attenuation: overall decrease in intensity including absorption and scattering.
- Absorption spectrum: plot of absorbed energy versus wavelength/frequency showing where a material absorbs.
- Adsorption: surface binding (contrast with bulk uptake).

If you want, I can give equations and worked examples for Beer–Lambert law, absorption cross sections, or compare absorption vs adsorption in more detail. Which context are you interested in?