AllChemicals — The Online Chemical Glossary | https://allchemicals.info/chemical/655-plasma
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Quick Reference
Also Known As
Ionised gas, fourth state of matter, plasma state, arc plasma
What is Plasma?
The fourth state of matter, consisting of a gas of ions and free electrons at very high temperatures. Plasma conducts electricity and responds to magnetic fields. It occurs in stars, lightning, fluorescent lights, and fusion reactors. About 99% of visible matter in the universe is plasma.
Properties & Characteristics
Plasma is the fourth state of matter, consisting of ionised gas (a mixture of free electrons and positive ions) in which the constituent particles respond collectively to electromagnetic fields. Plasma exists at very high temperatures (stars: 10⁶-10⁷ K; fusion reactors: 10⁸ K) or in low-pressure electrical discharges (fluorescent tubes, plasma processing equipment: ~10⁴ K). Natural plasmas include: stars, lightning, flames (weakly), and the sun's corona.
Uses & Applications
Plasmas are used in: semiconductor manufacturing (plasma etching and deposition), surface modification (plasma treatment of polymers for adhesion), plasma arc welding and cutting, lighting (fluorescent lamps, mercury vapour lamps), nuclear fusion research (tokamaks), and sterilisation of heat-sensitive medical devices (hydrogen peroxide plasma sterilisers).
Safety Information
High-temperature plasma arcs (welding, cutting) produce intense UV and visible radiation causing photokeratitis and skin burns. Plasma chemical processes use toxic precursors (silane, NF₃) and generate toxic by-products (HF from plasma etching). RF and microwave plasma generators emit non-ionising radiation. Appropriate shielding and PPE are required for all plasma equipment.
Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.
SynonymsIonised gas, fourth state of matter, plasma state, arc plasma
Frequently Asked Questions
The fourth state of matter, consisting of a gas of ions and free electrons at very high temperatures. Plasma conducts electricity and responds to magnetic fields. It occurs in stars, lightning, fluorescent lights, and fusion reactors. About 99% of visible matter in the universe is plasma.
Plasmas are used in: semiconductor manufacturing (plasma etching and deposition), surface modification (plasma treatment of polymers for adhesion), plasma arc welding and cutting, lighting (fluorescent lamps, mercury vapour lamps), nuclear fusion research (tokamaks), and sterilisation of heat-sensit…
High-temperature plasma arcs (welding, cutting) produce intense UV and visible radiation causing photokeratitis and skin burns. Plasma chemical processes use toxic precursors (silane, NF₃) and generate toxic by-products (HF from plasma etching). RF and microwave plasma generators emit non-ionising r…
Editorial standards: Chemical data is sourced from peer-reviewed literature,
CAS Registry, NIST WebBook, and PubChem. Safety information reflects guidance from OSHA, ECHA,
and IAEA. For educational purposes only — always consult official SDS documentation and qualified
professionals before handling chemicals.
