Atom or group of atoms carrying a positive electric charge, indicated by a superscript plus sign after the chemical symbol. Cations in a liquid subjected to an electric field collect at the negative pole (cathode). Examples include sodium (Na^+), calcium (Ca^2+), and ammonium (NH4^+; see ammonia). See also ion; Compare anion
Positively charged ion in solution When minerals dissolve in water, they form ions that have a tiny positive or negative electrical charge John Comer, Indiana Geological Survey
a positively charged ion in an electrolyte solution, attracted to the cathode under the influence of a difference in electrical potential Sodium ion (Na+) is a cation