ion with fewer electrons than protons (e.g. K+ (potassium ion)) while an anion is a negatively charged ion with more electrons than protons. (e.g. Cl-...

The anion gap (AG or AGAP) is a value calculated from the results of multiple individual medical lab tests. It may be reported with the results of an...

High anion gap metabolic acidosis is a form of metabolic acidosis characterized by a high anion gap (a medical value based on the concentrations of ions...

In chemistry, the cyclopentadienyl anion or cyclopentadienide is an aromatic species with a formula of [C 5H 5]− and abbreviated as Cp−. It is formed...

and anions simultaneously. However, the simultaneous exchange of cations and anions is often performed in mixed beds, which contain a mixture of anion- and...

types of ion-exchange resin, that differ in composition if the target is an anion or a cation. Most commercial resins are made of polystyrene sulfonate, followed...

The chloronitramide anion, also known as chloro(nitro)azanide, is a recently (2024) identified chemical byproduct of the disinfectant chloramine. It is...

Normal anion gap acidosis is an acidosis that is not accompanied by an abnormally increased anion gap. The most common cause of normal anion gap acidosis...

of metabolic acidosis. The term "anion gap" without qualification usually implies serum anion gap. The "urine anion gap" is a different measure, principally...

An anion exchange membrane (AEM) is a semipermeable membrane generally made from ionomers and designed to conduct anions but reject gases such as oxygen...

own in any of three forms: methanide anion (CH−3), methylium cation (CH+3) or methyl radical (CH• 3). The anion has eight valence electrons, the radical...

In chemistry, the cyclooctatetraenide anion or cyclooctatetraenide, more precisely cyclooctatetraenediide, is an aromatic species with a formula of [C8H8]2−...

In organic chemistry, a radical anion is a free radical species that carries a negative charge. Radical anions are encountered in organic chemistry as...

inorganic cyanides, the cyanide group is present as the cyanide anion −C≡N. This anion is extremely poisonous. Soluble salts such as sodium cyanide (NaCN)...

In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative...

is the polyatomic hydrogen sulfate anion (HSO−4). The removal of another hydrogen ion produces the sulfate anion (SO2−4). There are several patterns...

An alkaline anion-exchange membrane fuel cell (AAEMFC), also known as anion-exchange membrane fuel cells (AEMFCs), alkaline membrane fuel cells (AMFCs)...

In condensed matter physics and inorganic chemistry, the cation-anion radius ratio can be used to predict the crystal structure of an ionic compound based...

Anion-exchange chromatography is a process that separates substances based on their charges using an ion-exchange resin containing positively charged...

In chemistry, an oxocarbon anion is a negative ion consisting solely of carbon and oxygen atoms, and therefore having the general formula C xOn− y for...

The hydrogen anion, H−, is a negative ion of hydrogen, that is, a hydrogen atom that has captured an extra electron. The hydrogen anion is an important...

Azanide is the IUPAC-sanctioned name for the anion NH−2. The term is obscure; derivatives of NH−2 are almost invariably referred to as amides, despite...

Superelectrophilic anions are a class of molecular ions that exhibit highly electrophilic reaction behavior despite their overall negative charge. Thus...

Anions that interact weakly with cations are termed non-coordinating anions, although a more accurate term is weakly coordinating anion. Non-coordinating...

In chemistry, a hydride is formally the anion of hydrogen (H−), a hydrogen ion with two electrons. In modern usage, this is typically only used for ionic...

Anion exchange membrane (AEM) electrolysis is the electrolysis of water that utilises a semipermeable membrane that conducts hydroxide ions (OH−) called...

oxyanions, anions containing boron and oxygen, such as orthoborate BO3−3, metaborate BO−2, or tetraborate B4O2−7; or any salt of such anions, such as sodium...

system (e. g. hexafluorobenzene). The anion–π effect is advantageously exploited in chemical sensors for specific anions. Stacking (chemistry) Salt bridge...

derivative of citric acid; that is, the salts, esters, and the polyatomic anion found in solutions and salts of citric acid. An example of the former, a...

Nitrile anions is jargon from the organic product resulting from the deprotonation of alkylnitriles. The proton(s) α to the nitrile group are sufficiently...