Now, based on that, let's answer these two questions. It says, write balanced nuclear equations for each of the following positron emissions. So again, your positron will be a product. So here we're dealing with uranium 235. Uranium is U. On your periodic table, it's going to have an atomic number of 92. We emit a positron, so this is going to be:

U 235 92 → Pa 231 91 + e +

Next one is radon which is Rn. Radon has an atomic number of 86. We emit a positron. So now, the element is still going to be 222 and 85 +1 gives me the 86. So, that's Actinium. So, these would be two examples of our positron emission:

Rn 222 86 → Ac 222 85 + e +