Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
Related to hydrogen ion: hydrogen ion concentration
an atom or group of atoms having a positive (cation) or negative (anion) electric charge by virtue of having gained or lost an electron; substances forming ions are called electrolytes. adj., adj ion´ic.
dipolar ion an ion that has both positive and negative regions of charge.
hydrogen ion the positively charged hydrogen atom (H+), which is the positive ion of all acids. See also hydrogen ion concentration.
hydroxyl ion the negatively charged group, OH−, present to excess in alkaline solutions.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
hy·dro·gen ion (H+),
a hydrogen atom minus its electron and therefore carrying a unit positive charge (that is, a proton); in water, it combines with a water molecule to form hydronium ion, H5O2+, H7O3+, etc.
Farlex Partner Medical Dictionary © Farlex 2012
hy·dro·gen ion(H+ hī'drō-jen ī'on)
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 the hydronium ion, H3O+.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
hydrogen ionA free proton, which is the positively charged nucleus of a hydrogen atom.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005