Question

If an ion contains 10 electrons, 12 protons, and 13 neutrons, what is the ion's charge?

Answer 1

The number of neutrons is a distractor. Only the number of electrons versus the number of protons determines ionic charge. The charge of the ion is `2+`.

Explanation:

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.

For example, we could represent the deuterium isotope as `""^2H`. Because it is an hydrogen atom, `Z` `=` `1`; there is `1` proton, `1` positively charged nuclear particles. Because this is a neutral atom, I know there is `1` electron. But, there is another massive particle in the nucleus (why?), a neutron, and here deuterium is distinguished from the common variety of `""^1H` nucleus.

So, can you give a complete description of this isotope? You will need a Periodic Table.