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Related to anion: anion exchange, anion gap


(ăn`ī'ən), atom or group of atoms carrying a negative charge. The charge results because there are more electrons than protons in the anion. Anions can be formed from nonmetals by reduction (see oxidation and reductionoxidation and reduction,
complementary chemical reactions characterized by the loss or gain, respectively, of one or more electrons by an atom or molecule. Originally the term oxidation
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) or from neutral acids (see acids and basesacids and bases,
two related classes of chemicals; the members of each class have a number of common properties when dissolved in a solvent, usually water. Properties
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) or polar compounds by ionization. Anionic species include Cl, SO4−−, and CH3COO. Highly colored intermediates in organic reactions are often radical anions (anions containing an unpaired electron). Saltssalt,
chemical compound (other than water) formed by a chemical reaction between an acid and a base (see acids and bases). Characteristics and Classification of Salts

The most familiar salt is sodium chloride, the principal component of common table salt.
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 are made up of anions and cationscation
, atom or group of atoms carrying a positive charge. The charge results because there are more protons than electrons in the cation. Cations can be formed from a metal by oxidation (see oxidation and reduction), from a neutral base (see acids and bases) by protonation, or
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. See ionion,
atom or group of atoms having a net electric charge. Positive and Negative Electric Charges

A neutral atom or group of atoms becomes an ion by gaining or losing one or more electrons or protons.
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An ion that is negatively charged.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


a negatively charged ion; an ion that is attracted to the anode during electrolysis
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005


(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 ?
Corrosion inhibitor anion (V[O.sub.3.sup.-], Mo[O.sub.4.sup.2-], and 2-MBT)-intercalated ZnAl-LDH-N[O.sub.3.sup.-] films have been successfully synthesized on aluminum alloy 2024 substrate.
Anion gap (AG) was calculated by using the equation Na+ " (HCO3" + Cl") and the delta bicarbonate by HCO"3 " 24.
Although superoxide anion production is essential for bacterial cell killing, the subsequent release of hydrogen peroxide and other additional reactions produces more dangerous ROS, including singlet oxygen and the hydroxyl radical.Although not a free radial, singlet oxygen can be formed in some radical reactions and can also lead to others since it is one of the most active intermediates involved in biochemical reactions.
Given the improving anion gap and the lack of clinically relevant acidemia, there was debate about whether this patient had actually ingested ethylene glycol (EG) or had instead ingested propylene glycol (found in "safer" antifreezes) or isopropyl alcohol.
The nanohybrids containing hydroxycinnamate isomers were prepared from ZC-Ac by anion exchange; they are referred to herein as ZC-o-HCn, ZC-m-HCn, and ZC-p-HCn for compounds containing the orthoisomer, metaisomer, and paraisomer, respectively.
Three approaches have been applied to control Br[O.sub.3.sup.-] anion in water: (1) removal of the bromate precursors before ozonation such as bromide and natural organic matters (NOM), (2) control of bromate formation during ozonation process by controlling the operating conditions, and (3) the removal of bromate after formation called post-treatment [9].
Activated carbon is a good choice to be used for the decontamination of water from chromate anion because of its high surface area and excellent performance as compared to its counterparts reported in the literature [20].
While lithium ions are positive (called cations), the fluoride ions used in the new study bear a negative charge (and are called anions).
In the UV spectrum, a new absorption band appeared at about 485 nm for the solution of L containing hydroxide anion, indicating an anion-induced deprotonation of L due to the removal of NH protons by highly basic O[H.sup.-].
Travel agencies normally develop and market tour programs, and have their subcontractors run them Nearly 90 percent of 'anion latex' products sold were made with monazite powder _ an ore containing radioactive thorium that emits radon as it decays.