cation

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cation

(kăt'ī`ən), 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 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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), from a neutral base (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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) by protonation, or from a polar compound by ionization. Cationic species include Na+, Mg++, and NH4+. The cations of the transition elementstransition elements
or transition metals,
in chemistry, group of elements characterized by the filling of an inner d electron orbital as atomic number increases.
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 have characteristic colors in water solution. 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 cations and anionsanion
, 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 reduction) or from neutral acids (see acids and bases) or polar compounds
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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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.

cation

[′kat‚ī·ən]
(chemistry)
A positively charged atom or group of atoms, or a radical which moves to the negative pole (cathode) during electrolysis.

cation

a positively charged ion; an ion that is attracted to the cathode during electrolysis
References in periodicals archive ?
In this study, scientists investigated cation diffusion mediated by defects in the pyrochlore gadolinium titanium oxide (Gd2Ti2O7).
The scientists show that the guanidinium cation inserts into the crystal structure of the perovskite and enhances the material's overall thermal and environmental stability, overcoming what is known in the field as the "Goldschmidt tolerance factor limit.
Furthermore, Rengasamy and Marchuk (2011) also found that CROSS measured in soil solutions was strongly correlated with the ratio of exchangeable cations (ECR):
See sidebar, 'Why do cations with the same valence have different effects on soil permeability?
2 showed that the oxygen-binding abilities of CoL were enhanced by the alkaline cations to different extent.
In this work, we propose that appearance of overshooting effect may be attributed to the chelation between cations and the anionic groups on the polymer chains, which leads to the variation of crosslinking degree and the reorganization of the gel structure.
The need for selective reagents and processes for species with similar chemical properties still renders the investigations on the interaction of metal cations with macrocyclic ligands.
The main objective of this research was to convert rice husk and canola stalk to activated carbon and also evaluation of their sorption capacity to remove Ca and Mg as main cations causing hardness.
The role of divalent cations was determined by growing Listeria biofilms on stainless steel and adding EDTA at various times.
Addition of chloride to a prepartal diet high in cations increase 1,25--dihydroxyvitamin D response to hypocalcemia preventing milk fever.
There was interest to study such properties of received phosphate cation-exchange resin as sorption ability to ions of copper, nickel, calcium, sodium, cobalt and uranyl; to study influence of various factors on process sorption of these cations, and also their mechanism of sorption with application of the IR-spectroscopical analysis.
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