 OK, so let's try this one. It says calculate the number of protons, neutrons, and electrons in fluorine 19. So if it says that to you, you're going to have to remember how to write that. So fluorine 19 is just the elemental symbol. And remember, we put the mass number in the top left. And remember, this is one particular atom that we're talking about. So it's not like that weighted average that had. That was the 18.99 for whatever. So you'll see it written like this a lot of times. Sometimes you'll just see the atomic number written in there, but not always, because of course, if you got this atomic number of 9, or if you got fluorine, of course, that's the only atomic number it could be, or the only atom it could be. So fluorine 19, I guess it's written like this in the problem. Then it asks, how many protons, neutrons, and electrons are in this? So number of protons, electrons. The atomic number and the number of protons are the same number. So the atomic number is 9, so the number of protons is 9. Is it neutral atom? Because there's no charge there. We'll talk more about that later. I guess we haven't really gotten to ions. But of course, in the picture, it says charge goes there. And there's not anything there. So the number of electrons is the same as the number of protons? 9. And the number of neutrons is just the mass number minus the, if something says to you, you're to remember, you don't even really need that, because it's implied.