# How many electrons does copper have?

Oct 12, 2016

If you are doing your chemistry/physics homework, there should be a Periodic Table by your side. The Periodic Table tells me that $Z$, the atomic number for copper metal, is $29$.
What does this mean? It means that there are $29$ protons, 29 massive, positively charged particles in the element's nucleus. This specific number of protons defines the atom as a $\text{copper atom}$.
And thus if there 29 positive charges in the nucleus, there must also be 29 negative charges associated with the neutral atom, and these are supplied by the electron. And so (finally!), the number of electrons is $29$ for the neutral copper atom; 29 electrons whizz about the copper nucleus.