Akademik

An atom or group of atoms carrying an electric charge by virtue of having gained or lost one or more electrons. Ions charged with negative electricity (anions) travel toward a positive pole (anode); those charged with positive electricity (cations) travel toward a negative pole (cathode). Ions may exist in solid, liquid, or gaseous environments, although those in liquid (electrolytes) are more common and familiar. [G. i., going]

- aquo-i. aquo-i..

- dipolar ions ions possessing both a negative charge and a positive charge, each localized at a different point in the molecule, which thus has both positive and negative “poles”; amino acid s are the most notable dipolar ions, containing a positively charged NH₃⁺ group and a negatively charged COO⁻ group at neutral pH. SYN: amphions, zwitterions.

- gram-i. gram-i..

- hydride i. the H⁻ i., transferred to acceptor molecules in some biologic oxidations.

- hydrogen i. (H⁺) a hydrogen atom minus its electron and therefore carrying a unit positive charge ( i.e., a proton); in water, it combines with a water molecule to form hydronium i., H₃O⁺.

- hydronium i. the hydrated proton, H₃O⁺, a form in which hydrogen i. exists in aqueous solutions; also, H₃O⁺ H₂O, H₃O⁺ 2H₂O, etc. SYN: oxonium i..

- oxonium i. SYN: hydronium i..

- sulfonium i. a compound in which a sulfur atom has three single covalent bonds and therefore has a positive charge analogous to the nitrogen of an ammonium compound; e.g., S-adenosyl-l-methionine.

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ion 'ī-ən, 'ī-.än n

1) an atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one or more electrons see ANION, CATION

2) a charged subatomic particle (as a free electron)

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, ionization.