 Okay, let's do one last one of these for today. Calculate the number of protons, neutrons, and electrons in 4 on 11. So, Boron's elemental symbol is B, Boron 11, mass number, superscript in the top left. If you want to, you can put the atomic number there too. 5, okay? The atomic number tells you straight away the number of protons. 5, same as the number of electrons. 5, what's the number of neutrons? Well, it's going to be the mass number minus the number of protons for the atomic number. It's neutrons in Boron 11. And again, this is an isotope of Boron. So this mass number refers to the mass of this particular Boron. Not all the Boron happens in the universe. Okay, so hopefully that helps.