How are ions represented when they have a positive charge?

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ncchemist eNotes educator| Certified Educator

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:

`Na^+`

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:

`Ca^(2+)`