If an ion contains 10 electrons, 12 protons, and 13 neutrons, what is the ion's charge?
Of course, the electronic charge of the ion depends on the number of positively charged nuclear particles, versus the number of fundamental negatively charged particles: i.e. protons versus electrons. Since there are 2 more positive charges than electrons, the charge is +2. Now, not only can we determine the charge of the ion, we can determine the identity of the ion. How? Because the number of protons, Z, positively charged nuclear particles, determines the identity of the element. What is it? We have the identity of the element, the number of neutrons, neutrally charged, massive nuclear species, tells us which isotope.
