negative ion

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Negative ion

An atomic or molecular system with an excess of negative charge. Negative ions, also called anions, are formed in attachment processes in which an additional electron is captured by an atom or molecule. Negative ions were first reported in the early days of mass spectrometry. It was soon learned that even a small concentration of such weakly bound, negatively charged systems had an appreciable effect on the electrical conductivity of gaseous discharges. Negative ions now play a major role in a number of areas of physics and chemistry involving weakly ionized gases and plasmas. Applications include accelerator technology, injection heating of thermonuclear plasmas, material processing, and the development of tailor-made gaseous dielectrics. In nature, negative ions are known to be present in tenuous plasmas such as those found in astrophysical and aeronomical environments. The absorption of radiation by negative hydrogen ions in the solar photosphere, for example, determines the Sun's spectral distribution. See Ion sources

McGraw-Hill Concise Encyclopedia of Physics. © 2002 by The McGraw-Hill Companies, Inc.

negative ion

[′neg·əd·iv ′ī‚än]
An atom or group of atoms which by gain of one or more electrons has acquired a negative electric charge.
An electron or negatively charged subatomic particle.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


(1) (IDL On the Net) See IDL.

(2) (ION) An NVIDIA graphics platform typically used in Atom-based netbooks. See Intel Atom.

(3) An ion is an atom with fewer or greater electrons than normal as a result of radiation or chemical reaction. A positive ion, called a "cation" (pronounced "cat-eye-en"), has one or more electrons stripped out, which means it has fewer electrons in its electron shells than it has protons in its nucleus. A negative ion, called an "anion" (pronounced "an-eye-en"), is an atom that has one or more electrons forcibly added.

Cations, Anions, Cathodes and Anodes
Although one might think cations are in cathodes and anions are in anodes, the opposite is true. When the terms were coined, the concept was that positive cations were attracted to the negative cathode, and negative anions were attracted to the positive anode.

Batteries Contain Positive and Negative Ions
In a battery, there are positive ions on one side and negative ions on the other. When a conductor is placed in between to complete the circuit, the electrons flow from the negative ions to the positive side where they join the positive ions. See ion deposition.
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References in periodicals archive ?
Negative ions are invisible molecules found in the forest, the mountains, and near water, such as oceans and waterfalls.
The structures and morphologies of VST and copolymer p (VST/MMA/BA) were characterized by IR, SEM, and EDX, and their mechanical properties and performances in far-infrared radiation and negative ion release were evaluated quantitatively.
In the negative ion mode, type I saponins produce the same fragment ions at m/z 273 [[[C.sub.19][H.sub.29]O].sup.-], 255 [[[C.sub.19][H.sub.27]].sup.-] , 301 [[[C.sub.21][H.sub.33]O].sup.-], and 283 [[[C.sub.21][H.sub.31]].sup.-]; types II to IV produce the same fragment ions at m/z 271 [[[C.sub.19][H.sub.27]O].sup.-], 253 [[[C.sub.19][H.sub.25]].sup.-], 299 [[[C.sub.21][H.sub.31]O].sup.-], and 281 [[[C.sub.21][H.sub.29]].sup.-]; and type V saponins produce the same fragment ions at m/z 269 [[[C.sub.19][H.sub.25]O].sup.-] and 251 [[[C.sub.19][H.sub.23]].sup.-].
Negative ions still influenced the cells' response to a given salt, with the effect of the negative ion remaining dependent on the ion's size.
3: MS/MS spectra of metabolite M1 obtained using negative ion electrospray (A) and its proposed decomposition mechanism (B).
Negative ions are fragile fascinating quantum systems having lots of interesting physical and chemical properties.These are being studied due to their increasing importance in applied sciences[11, 12].
The negative ion stimulation with the proposed device performed the best in the in-vitro experiment of the three statements.
These advanced lighting products contain built-in negative ion generators that release negative ions into the air, attracting unhealthy positive particles, such as dust, mold, pet dander and even tobacco smoke.
The facility will have two test stands, one for testing negative ion sources and one for testing a full-size, one-megavolt ITER neutral beam injector.
SGP-SNA adopts the special film, which generates negative ion, to wrap sushi.
The Waters Quattro Premier XE includes the improved WHISPER dynolite photomultiplier detector, which reduces detector noise in both negative and positive ion modes and improves instrument sensitivity in negative ion mode.
Papers are in sections on neutral beam systems, fundamental processes, hydrogen and deuterium negative ion sources, applications, and extraction, acceleration, transport, and neutralization of ions.