Band of Stability: Beta Decay - Online Tutor, Practice Problems & Exam Prep

Beta decay is a nuclear process that isotopes undergo to achieve stability when they have an excess of neutrons. Isotopes located to the left of the band of stability on the nuclear chart are prone to beta decay, which allows them to convert these extra neutrons into protons. This transformation results in a decrease in the neutron count and an increase in the proton count, shifting the isotope towards the band of stability. An example of this process is the transformation of palladium-107 into silver-107 through the emission of a beta particle. This decay helps isotopes achieve a more stable configuration by balancing their neutron-to-proton ratio.

Band of Stability: Beta Decay

Hey everyone. In this video we're going to take a look at beta decay. Here we're going to say that beta decay happens for isotopes to the left of the band of stability. Here we have our band of stability, which is this green curve and this blue area represents where isotopes that exist that will perform beta decay.

Now we're going to say here a good example is Palladium 107. Here it emits a beta particle in order to become silver 107. Now here we're going to say that those in the blue region, these are isotopes that have an excess of neutrons. Beta decay helps them to convert their neutrons or excess neutrons into protons.

If we look take a look here, we have neutrons over here. So what tends to happen is we're going to drop down a little bit in terms of the number of neutrons and we're going to shift to the right, increasing our number of protons. This allows us to fall within the band of stability and become a more stable isotope.

So just remember to the left of the curve we have beta decay. The whole purpose is to help reduce our number of neutrons, increase our number of protons that we fall within the band of stability.

Band of Stability: Beta Decay Example

Here it says to provide the identity of the daughter nuclide created from the beta decay of magnesium 28. So here we're dealing with magnesium, it's mass numbers 28 and if we look on the periodic table, it's atomic number is 12. It's undergoing beta decay, so it's going to emit an electron and we just need to make sure that our mass numbers are the same on both sides and our number of protons are the same on both sides.

Here we have 28 on the left side, so we need a total of 28 for our mass number. On the product side. The electron contributes nothing to the mass number, so our new isotope has to have 28. Here on the left side we have 12 protons. On the right side we still need to have 12 protons, but here we have a -1. So the number here would have to be 13 because 13-1=12.

Looking on the periodic table, the only element that has an atomic number of 13 is aluminum. So the beta decay of Magnesium 28 produces Aluminum 28, meaning that option D is our final answer.

How many beta decays would it take to transform tungsten-184 into iridium-184?

a) 5                                         

b) 1                                          

c) 3                                               

d) 4

• A. 5
• B. 1
• C. 3
• D. 4