Absorption band

<p>In <a href="/facts/Spectroscopy/mj71FuNK">spectroscopy</a>, an absorption band is a range of <a href="/facts/Wavelength/kcJU0ymz">wavelengths</a>, <a href="/facts/Frequency/QUSbPaW8">frequencies</a> or energies in the <a href="/facts/Electromagnetic_spectrum/24LARvFY">electromagnetic spectrum</a> that are characteristic of a particular transition from initial to final state in a substance.
</p><p>According to <a href="/facts/Quantum_mechanics/BRc3Mzgr">quantum mechanics</a>, <a href="/facts/Atom/FoQ4kGN5">atoms</a> and <a href="/facts/Molecule/N9ljSfFq">molecules</a> can only hold certain defined quantities of <a href="/facts/Energy/wd8PrQM7">energy</a>, or exist in specific <a href="/facts/Quantum_state/7jbxd7Dx">states</a>. When such <a href="/facts/Quantum/4x5QTxGB">quanta</a> of <a href="/facts/Electromagnetic_radiation/Ynx7ujCW">electromagnetic radiation</a> are emitted or absorbed by an atom or molecule, energy of the radiation changes the state of the atom or molecule from an <a href="/facts/Ground_state/ML7cfCug">initial state</a> to a <a href="/facts/Excited_state/czcLYNnr">final state</a>.
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Absorption band open-in-new

Absorption band