What does ionization mean?
Ionization is the process of producing ions, electrically charged atoms or molecules. It commonly occurs when energetic radiation or an electrical discharge removes electrons from neutral atoms, leaving positive ions and free electrons; electrons can also attach to atoms or molecules to form negative ions. The process is important in fields such as chemistry, physics, medicine, and telecommunications, and it is investigated through measurements of ionization energy, ionization chambers, and the degree of ionization of a substance. Ionization is distinct from chemical dissociation: although both can involve a substance separating into smaller components, ionization specifically concerns the creation or transfer of electric charge. In everyday language, the word may evoke the charged air around a lightning strike or the glowing discharge in a fluorescent tube, both consequences of energetic particles ionizing surrounding gas.
nounThe process of converting atoms or molecules into electrically charged particles called ions, typically by removing or adding electrons. It may occur naturally, as in the ionization of gases by radiation, or be induced artificially, as in a gas discharge tube.
- The chemical or physical process of forming ions, especially by removing electrons from atoms or molecules through radiation, electrical discharge, or other energetic effects.
"The intense ultraviolet radiation caused the ionization of the surrounding gas."
"The device detects ionization events produced by incoming radiation."
"Salt dissolution in water is not necessarily accompanied by ionization, since ionic compounds may already consist of ions."
The plural is uncommon and is used when referring to separate instances of ionization or distinct ionization events.
"The laboratory recorded ionizations caused by the radioactive sample."
When radiation is strong enough to knock electrons away from atoms, it leaves behind a trail of charged particles—and that charged trail is the signature of ionization.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does ionization come from?
Ionization is formed from "ion" and the suffix "-ization," a combining form associated with the process of making or becoming something. The term developed in the 19th century as scientific understanding of charged particles expanded. Its cognate family includes "ionic," "ionosphere," and "ionospheric," all of which share the same scientific root.
Related word forms
How ionization is actually used
The term is primarily technical and is used in chemistry, physics, atmospheric science, and radiation detection. The spelling is typically "ionization" in US English and "ionisation" in British English.
Easily confused with ionization
Ionization specifically forms ions by adding or removing electrons, whereas dissociation describes a chemical process in which a substance separates into smaller components, which may or may not be charged.