hydrogen ion

== English == === Noun === hydrogen ion (plural hydrogen ions) (chemistry) Used other than figuratively or idiomatically: see hydrogen,‎ ion.: H- or H+ (chemistry) a proton combined with one or more water molecules; usually written H3O+ and called the hydronium ion though is best considered as H9O4+ but is often written H+(aq) for simplicity (chemistry) a bare hydrogen nucleus; a proton, deuteron or triton ==== See also ==== hydronium hydroxide hydroxyl pOH pH