Help with understanding isotopes?
Well this is on my mid-term study guide and I don't get it. I'm just looking for help, not just answers. Here's the question:
"According to Wikipedia, 'Naturally occurring zinc (Zn) is composed of the 5 stable isotopes 64Zn, 66Zn, 67Zn, 68Zn, and 70Zn with 64Zn being the most abundant'. Explain what is meant by the term "isotopes". For each of these 5 isotopes, calculate the number of protons and neutrons in the nucleus."
I kind of get what isotopes are, that they are atoms that have different mass numbers but the same atomic mass, but that's it.
Help, please? >_<