Anions and Cations
"Cation" and "Anion" redirect here. For the particle physics/quantum computing concept, see Anyon. For other uses, see Ion (disambiguation).Since the electric charge on a proton is equal in magnitude to the charge on an electron, the net electric charge on an ion is equal to the number of protons in the ion minus the number of electrons.
An anion (−) ( /ˈæn.aɪ.ən/ AN-eye-ən), from the Greek word ἄνω (ánō), meaning "up", 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 (+) ( /ˈkæt.aɪ.ən/ KAT-eye-ən), from the Greek word κατά (katá), meaning "down", is an ion with fewer electrons than protons, giving it a positive charge.
There are additional names used for ions with multiple charges. For example, an ion with a -2 charge is known as a dianion and an ion with a +2 charge is known as a dication. A zwitterion is a neutral molecule with positive and negative charges at different locations within that molecule.
Read more about this topic: Ion