Band of Stability: Alpha Decay & Nuclear Fission - Video Tutorials & Practice Problems

Intro to Band of Stability

Now, before we talk about alpha decay and nuclear fission, it's important to understand that isotopes that lie outside the ban or valley of stability are considered unstable, radioactive isotopes. And we're gonna say these isotopes will alter their number of neutrons and or protons to move closer to the band or valley of stability. Now, we know they do this predominantly based on our header that they do it through alpha decay and nuclear fission. But they can also do it through beta decay, they could do it through electron capture or even positron emission. So these are just the different avenues that our particular isotope can take in order to get closer and fall within the band of stability and reach a greater level of nuclear stability. So keep this in mind when looking at any isotope and comparing it onto the neutron to proton plot.

Band of Stability: Alpha Decay

You were going to say that alpha decay happens for isotopes in the top right corner of the neutron. The proton plot, we're gonna say these is isotopes have an excess of neutrons and protons. If we take a look here, we have platinum 213, here it lies within our red region which means it wants to do alpha decay. In this case here, we have al decay of platinum 213. It would emit an alpha particle as a product and as a result, it would create bits myth 209 by doing this, we're going to say, what does it do? Well, if we look at our plot, we know that on our y axis, we have our number of neutrons on our x axis, we have our number of protons here. It's decreasing, its number of neutrons, decreasing its number of protons so that we can fall within the band or value of stability and create a more stabilized. This, in this case would be bismuth 209. It's giving us this green dot Right here. Now, this happens with isotopes with atomic masses of that are equal to a greater than 210 AM U, we're going to say this whole process is just helping to decrease the total number of nucleons, your total number of protons and neutrons because there's an excess of both of them. OK. So, in this case, again, we're moving from the top right section, this red area into the more stable green area which represents our band or valley of stability.

Band of Stability: Alpha Decay & Nuclear Fission Example

He says, which daughter New Clyde would resign in the band of stability created from the alpha decay of lead. 212. All right. So lead 212, lead is PB and 212 is its mass number. If we look on the periodic table, we'll see that the atomic number of lead is 82. We're told that it's undergoing alpha decay. So we're gonna produce an alpha particle as a product. We are mass numbers to be the same on both sides and our total number of protons to be the same on both sides. We have 212 on the reactant side. So we need 212. On the product side, we already have four, which means we need another 208. Here we have 82 protons on the reactant side, we need 82 protons. On the product side, we already have two from the alpha particle, which means we need another 80 from our new isotope. If we look on the periodic table, the element that has an atomic number of 80 would be mercury HG. So we've just created mercury two oint. So option B would be our final answer.

Band of Stability: Nuclear Fission

Under nuclear fission, we're going to shoot a neutron at the nucleus of an isotope. And from this, we're gonna release an extremely large amount of energy. So this is a manmade process with the main objective is abs extracting as much energy in this process. Now, an additional benefit to this is that large heavy elements, those that are greater than 2:09 a.m. B. So the radioactive ones can be split into two lighter dotter nuclide. Here, this will help help to drastically lower the total number of nucleons. So protons and neutrons for an isotope. So here we take a look at this image. We're going to say that under nuclear fission again, we inject a neutron into the nucleus of an isotope. The isotope in question is plutonium 239. Remember a neutron has the mass number one. And since it's neutral, it's atomic number is zero. When we inject this neutron into plutonium 239 we create a very unstable plutonium 240. This becomes our parent newly. Here it's this that undergoes nuclear fission. If we were to take a look at the neutron to proton plot, we see that the plutonium 240 is deeply in the red section of the plot. And we're going to say it undergoes nuclear fission. It's going to break apart, it breaks apart to give us zirconium 103 and bury in 134. In addition to this, it's gonna give us three neutrons and our main objective all of this energy. So 207.1 mega electron volts, which is an incredible amount of energy. Now, another thing that happens because of nuclear fission is that we create these three neutrons. What started this whole process? A neutron, a neutron was injected into the nucleus of a plutonium 239 isotope, we just created three additional neutrons. Each of those neutrons could seek out another plutonium 2 39 2 39 and start this process all over again, creating more data isotopes products and even more energy and this could keep going on and on and on which is why we say that this can do a chain reaction. OK. So the newly created neutrons further react, they can further react with additional plutonium 230 knots. Right. So what effect does this have in terms of our plot? Well, we see that we had our plutonium 240 over here and it created two daughter isotopes as products which fall within the band of stability. So we help to create two more stable isotopes as a result, right? So again, our primary objective is to create energy and create a ton of energy through chain reaction. But an added benefit to this is that we create don product nuclei nucleons that are within the band of stability, something that's even more stable. Right? So keep this in mind when we're looking at a nuclear fission reaction.

Band of Stability: Alpha Decay & Nuclear Fission Example

Now, nuclear fission is a commonly occurring process for uranium 235 provide the identity of the missing dot nuclide produced at the end of the reaction. All right. So we injected a neutron uranium 235 which created uranium 236 which is unstable and it undergoes nuclear fission. We see the energy that's produced. We see one of the daughter products and we see our three neutrons being created. Remember that your mass number, total mass number on both sides have to be the same and your total number of protons on both sides have to be the same here. We have 236 on this reactant side here and we need 236 on the product side. Well, we have 141 here and then three times one is three. So, so far we have 144. What number do we need to have for a to also have a total mass number of 236. So 236 minus 144 will give me 92. So here it would be 92. And then if we look at the number of protons, we have 92 on the reactant side. Here, this is zero. So it doesn't contribute. Here, we are 56. So if we do 92 minus 56 here, that'll give me my number of protons as being equal to 36. If we look on the periodic table, what almond has in atomic number 36 and B krypton. So here this would be krypton 92 which gives me option B as my correct answer.

Which of the following is a potential daughter nuclide created from the nuclear fission of uranium-233 that resides near the band of stability? 

a) Strontium-94     

b) Radon-222

c) Curium-247

d) Thorium-232

• A. Strontium-94
• B. Radon-222
• C. Curium-247
• D. Thorium-232