ion

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ion Atom or group of atoms with an electric (positive or negative) charge resulting from the loss or gain of one or more electrons. Positive ions are called cations and move towards the cathode in electrolysis; negative ions are called anions and move towards the anode. Ion exchange is when a compound's ions are replaced by ions from another compound with the same charge, and this process is used to remove the hardness of water. The region of ions in the atmosphere is the ionosphere. See also ionic bond; ionic compound

Ion

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Ion

Forms of ordinary chemical elements that have gained or lost electrons from their orbit around the atomic nucleus and, thus, have become electrically charged. Positive ions (those that have lost electrons) are called cations because when charged electrodes are placed in a solution containing ions the positive ions migrate to the cathode (negative electrode). Negative ions (those that have gained extra electrons) are called anions because they migrate toward the anode (positive electrode). Environmentally important cations include the hydrogen ion (H+) and dissolved metals. Important anions include the hydroxyl ion (OH-) as well as many of the dissolved ions of nonmetallic elements.

See also Ion exchange; Ionizing radiation

ion

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i·on / ˈīən; ˈīˌän/ • n. an atom or molecule with a net electric charge due to the loss or gain of one or more electrons. See also cation, anion.

ion

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ion (I-ŏn) n. an atom or group of atoms that has lost one or more electrons, making it electrically charged and therefore more chemically active. See anion, cation, electrolyte.

ion

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ion An atom that has acquired an electric charge by the loss (cation; positive charge) or gain (anion; negative charge) of one or more electrons.

ion

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ion An atom that has acquired an electric charge by the loss (cation; positive charge) or gain (anion; negative charge) of one or more electrons.

ion

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ion An atom or molecule that has lost or gained one or more electrons, and thus has an electric charge. Positively charged ions are known as cations, because they migrate towards the cathode (negative pole) in solution, while negatively charged ions migrate towards the positive pole (anode) and hence are known as anions.

ion

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ion An atom or group of atoms that has either lost one or more electrons, making it positively charged (a cation), or gained one or more electrons, making it negatively charged (an anion).

ion

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ion Atom that has acquired an electric charge by the loss (cation; positive charge) or gain (anion; negative charge) of one or more electrons.

ion

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ion XIX. — Gr. ión, prp. n. of iénai go.
Hence ionize XIX.