# What is the total number of electrons in an atom of Cu-65?

For a neutral ""^65Cu atom, there are...........
$\text{29 electrons......}$
An isolated, NEUTRAL atom has as many massive positive, nuclear particles in its nucleus, as there are electrons, negative extra-nuclear particles, that are conceived to whizz about the nucleus. The number of massive positive, nuclear particles gives $Z$, the atomic number, and this number defines the identity of the nucleus. For copper, $Z = 29$, and thus in the NEUTRAL atom there are 29 electrons.........How many neutrons are there?