Now, here, we have to write the balanced nuclear equations for each of the following alpha emissions. So, for an alpha emission again, that's the same thing as decay. That means that the alpha particle will be a product. So here we have Curium-248. Remember, these numbers here are atomic masses. You have to actually look on your periodic table to find out the atomic number of curium and bismuth. So, curium on our periodic table is 96. We know that we're going to basically emit an alpha particle. So, it's going to have to be a product. Again, we have 4 already, so we have to make sure that the new element next to it adds up to 248 on the other side. So it's going to be 244 +4 gives me 248. And down here, this has to be 94. And what does that give me? That gives me plutonium (Pu).
^{248} Cm → ^{244} Pu + ^4 HeAnd then, bismuth 207, that's the atomic mass. The atomic number on the bottom would be 83. So, we have Bi, we emit a Helium or alpha particle. So, we have 4 here but we need 207, so we have 203 over 81 and that gives me Thallium (Tl). It's that simple.
^{207} Bi → ^{203} Tl + ^4 HeNow, if they were to ask for an alpha absorption or alpha capture, then that means the alpha particles wouldn't be products, they'd be reactants. For example, you have ^{40}Ca which is calcium and then you do alpha capture. So, it will be on the same side. And then all you have to do is just add these numbers up. So, it would be 40 + 4 is 44, over 22, to give you your new element. So, you just look on your periodic table and see what element has an atomic number of 22, and that will represent an alpha capture.