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

1 Answer
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.