ANION AND CATION
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving the atom a net positive or negative electrical charge.
Ions can be created by both chemical and physical means. In chemical terms, if a neutral atom loses one or more electrons, it has a net positive charge and is known as a cation. If an atom gains electrons, it has a net negative charge and is known as an anion.
An anion (−) is an ion with more electrons than protons, giving it a net negative charge (since electrons are negatively charged and protons are positively charged).
A cation (+) is an ion with fewer electrons than protons, giving it a positive charge.