How are ions represented when they have a positive charge?
Charged chemical species are called ions. Positively charged ions are called cations and negatively charged ions are called anions. Cations are denoted with a positive sign (+) as a superscript at the end of the atom or chemical formula. Anions are denoted with a negative sign (-) as a superscript at the end of the atom or chemical formula. As an example, the sodium cation is written as:
If an ion has a positive charge greater than one, then the cation is written as the number of the charge followed by the + sign. As an example, the calcium cation is written as: