Anion

In an electrical field, anions are attracted to the positively-charged pole, which is called the anode.

An anion can be a negatively charged atom or group of atoms. In an electrolytic cell, anions are attracted to the positive electrode. Some common anions are the hydroxide ion (OH^–), the chloride ion (Cl^–), the nitrate ion (NO₃^–), and the bicarbonate ion (HCO₃^–). The single minus signs indicate that these ions carry one electron’s worth of negative charge. The carbonate ion (CO₃^2–), for example, carries two units of negative charge.

The names of anions consisting of single atoms (monatomic ions) end in the suffix -ide. Fluoride (F^–), sulfide (S^2–), and oxide (O^2–), are examples. A few polyatomic ions (ions with more than one atom) also have an -ide ending. The cyanide ion (CN^–) is an example.

The names of most polyatomic anions end in either -ate or -ite. For example, the most common polyatomic anions of sulfur are the sulfate (SO₄^2–) and sulfite (SO₃^–) ions. In pairs such as this one, the -ate suffix is used for the ion that contains sulfur in the higher oxidation number, and the -ite suffix for the ion with the lower oxidation number. The oxidation number of sulfur is six in the sulfate ion and four in the sulfite ion.

Anion

An anion is a negatively charged atom or group of atoms . Anions are attracted to the anode , or positive electrode, in an electrolytic cell. Some common anions are the hydroxide ion (OH-), the chloride ion (Cl-), the nitrate ion (NO3- ), and the bicarbonate ion (HCO3- ). The single minus signs indicate that these ions carry one electron's worth of negative charge. The carbonate ion (CO32- ), for example, carries two units of negative charge.

The names of anions consisting of single atoms (monatomic ions) end in the suffix -ide. Fluoride (F-), sulfide (S2-), and oxide (O2-), are examples of such ions. A few polyatomic ions (ions with more than one atom) also have an -ide ending. The cyanide ion (CN-) is an example.

The names of most polyatomic anions end in either -ate or -ite. For example, the most common polyatomic anions of sulfur are the sulfate (SO42- ) and sulfite (SO3- ) ions. In pairs such as this one, the -ate suffix is used for the ion that contains sulfur in the higher oxidation number, and the -ite suffix for the ion with the lower oxidation number. The oxidation number of sulfur is six in the sulfate ion and four in the sulfite ion.

anion (an-I-ŏn) n. a negatively charged ion, which moves towards the anode (positive electrode) when an electric current is passed through the solution containing it. Compare cation. a. gap the difference between the concentrations of cations (positively charged ions) and anions, calculated from the formula (Na⁺ + K⁺) – (HCO³⁻ + Cl⁻): it is used to estimate the unaccounted-for anions in the blood in cases of metabolic disturbance.

an·i·on / ˈanˌīən/ • n. Chem. a negatively charged ion, i.e., one that would be attracted to the anode in electrolysis. The opposite of cation.DERIVATIVES: an·i·on·ic / ˌanīˈänik/ adj.

anion A negative ion, i.e. an atom, or complex of atoms, that has gained one or more electrons and thereby carries a negative electric charge (e.g. Cl⁻, OH⁻, and SO²⁻₄). It is so called because when an electric current is passed through a conducting solution the negative ions present in the solution are attracted to the anode (the positive electrode). Compare cation.