This conveys matter from one place to the other. Faraday did not know the nature of these species, but he knew that since metals dissolved into and entered a solution at one electrode and new metal came forth from a solution at the other electrode that some kind of substance has moved through the solution in a current. This term was introduced (after a suggestion by the English polymath William Whewell) by English physicist and chemist Michael Faraday in 1834 for the then-unknown species that goes from one electrode to the other through an aqueous medium. So called because ions move toward the electrode of opposite charge. a cation is something that moves down (Greek kato κάτω kat-ion) and an anion is something that moves up (Greek ano ἄνω, an-ion). The word ion was coined from Greek ion, neuter present participle of ienai (Greek ἰέναι) "to go" from PIE root *ei- "to go.", cf.
In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and a positive ion. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. Because of their opposite electric charges, cations and anions attract each other and readily form ionic compounds. The net charge of an ion is non-zero due to its total number of electrons being unequal to its total number of protons.Ī cation is a positively charged ion with fewer electrons than protons while an anion is negatively charged with more electrons than protons. The negative charge of an electron is equal and opposite to charged proton(s) considered positive by convention. The charge of the electron is considered negative by convention. JSTOR ( September 2020) ( Learn how and when to remove this template message)Īn ion ( / ˈ aɪ ɒ n, - ən/) is a particle, atom or molecule with a net electrical charge.Unsourced material may be challenged and removed.
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