# How many protons and electrons are in a ""_29^64Cu^(2+) ion?

Dec 20, 2015

$29$ protons, $27$ electrons

#### Explanation:

The subscripted number, $29$, represents the number of protons.

The charge, superscript and to the right, shows how many electrons have been gained or lost.

Since one electron has a charge of $- 1$, a charge of $+ 2$ means that the ion has lost two electrons.

In a nonionic atom, the number of protons is equal to the number of electrons—that is, this atom would normally have $29$ electrons. However, since two electrons have been lost, the ion only has $27$ electrons.