An ion is a particle (an atom or molecule etc.) in which the total number of electrons and protons are not the same, giving a net charge unequal to zero. If there are more electrons than protons, the particle will exhibit a negative charge, and if there are less, a positive. An anion is a negatively charged ion, while a cation is positively charged.
Types of IonsEdit
An ion is classified into one or multiple groupings depending upon its charge, size and components.
A monatomic (or simple) ion is composed of only one atom. Simple ions are most commonly formed when a monatomic element gains or loses one or several electrons. Common monatomic ions are fomed as per
Cl + e-→Cl-
Na→Na+ + e-
A polyatomic ion is composed of two or several atoms.