absorpsioistä

Absorpsioista, or absorption spectra, are unique patterns of light that are absorbed by a substance. When white light, which contains all wavelengths, passes through a material, certain wavelengths are absorbed by the atoms or molecules within that material. The remaining wavelengths continue to pass through or are emitted, and this combination is what we observe. The specific wavelengths that are absorbed depend on the electronic structure of the substance. Electrons in atoms and molecules can only exist at discrete energy levels. When light of a specific energy (and thus wavelength) matches the energy difference between two of these levels, the electron can absorb that photon of light and jump to a higher energy level.

The resulting absorption spectrum is essentially a plot of light intensity versus wavelength, with dark lines or bands appearing at the wavelengths that were absorbed. Each element and compound has a unique absorption spectrum, much like a fingerprint. This makes absorption spectroscopy a powerful tool for identifying unknown substances. For instance, astronomers use absorption spectra of stars to determine their chemical composition by observing which wavelengths of starlight are absorbed by the elements in the star's atmosphere. In chemistry, it's used to identify and quantify dissolved substances in solutions. The principle is fundamental to understanding how matter interacts with electromagnetic radiation.