<P> In the physical sciences, an ion (/ ˈaɪən, - ɒn /) is a particle that has a non-zero net electrical charge, such as an atom or molecule whose total number of electrons is not equal to its total number of protons . A cation is a positively - charged ion, while an anion is negatively charged . Because of their opposite electric charges, cations and anions attract each other and readily form ionic compounds, such as salts . </P> <P> Ions can be created by chemical means, such as the dissolution of a salt into water, or by physical means, such as passing a direct current through a conducting solution, which will dissolve the anode via ionization . </P>

An anion is any atom or group of atoms with a positive charge