Positron Emission - Video Tutorials & Practice Problems

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A positron emission or positron decay occurs when an unstable nucleus ejects a positron particle to create a new element.

Understanding Positron Emission

A positron particle is referred to as the anti-electron particle because it looks like a positively charged electron.

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Positron Emission Concept 1

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Hey, guys, In this new video, we're gonna take a look at positron emission. So here, we're gonna say positive positron emission occurs when an unstable nucleus emits a positron. Now, what's a positron? A positron is an anti particle of the electron. Remember, the electron is represented by this. Ah, positron is the opposite of that. So it looks like an electron. But instead of it having a negative sign, it'll have the opposite sign. So it'll be a positive electron. So a positron is considered just a positive electron. I know this is weird, but again, remember, we're dealing with nuclear reactions. So a lot of unaccustomed things that we are not used to seeing do occur. And one of them is this positron. So we're gonna say here, here's our positron now, because we're talking about the word emission again, Emission would mean decay, which means that this positron would be a product. So let's think of an example here. Einstein has its own element named after him Einstein E um, so Einstein E, um, we'll deal with isotope to 53 of Einstein E. Um, So Einstein, um, is yes. On our periodic table, it has an atomic number of 99 we're going to emit a positron. And because we're emitting a positron, let's see. So because the atomic masses zero the new elements still gonna be 53. But because the bottom is one what number plus one gives me 99 it have to be on 98. So here, that would just be CF. So this would be an example of a positron decay or positron emission.

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Positron Emission Example 1

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now, based on that, let's answer these two questions. It says right balance nuclear equations for each of the following positron emissions. So again, you're positron will be a product. So here we're dealing with uranium to 35 uranium is you on your periodic table. It's gonna have an atomic number of 92. We emit a positron. So this is gonna be 2 35 and 91 plus one. It gives me 92 so 91 would be P a. Now, next one is radon, which is RN. Okay. Radan has an atomic number of 86. We admit a positron. So now the elements still gonna be 2. 22 and 85 plus one gives me the 86. So that's act idiom. Okay, so these would be two examples off our positron emission

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Positron Emission Example 2

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now following what we've learned so far about all the different types of the case and emissions out there. Let's try our best to answer this one. So here we're gonna say a nuclei I'd off Valium or not, Valium story, Um 2. 25 undergoes three off of the case for beta decays and a gamma emission. What is the product? So remember, thorium has an atomic number of 90. It's gonna undergo three off of the case and off of the case basically produced the helium or Alfa particle plus four baited a case. So that's four electrons being admitted, plus gamma, which is 0/0. So basically, when you have three helium particles being admitted, that's three times four, which is 12 3 times to which is six four times zero, which is 04 times negative one, which is negative for again. This is not the proper way to write it. I'm just combining all the math just to make it easier for us to see what the answer is. So we're gonna say 12 here, so the new element would have to be to 13 because 12 plus 2 13 would give me the 25 I started out with and then here six plus this negative four gives me too. So it has to be 88 here because 88 plus two will give me back the 90 I started out with. So then we're gonna say we have 88. So that is our A, which is radium. And because we underwent a gamma emission, Technically, this would be in an excited state. So we put little Asterix there to show that it's an excited state. So that's all we have to do. And this top equation will be the correct way to write the equation, remember? Oops, Remember, I just combined everything. I just combined everything here to make the math easier. Easier for us to see what's going on. But it's this top equation. That's the correct format that your professor will be looking for. So just remember, fundamentally decay. The mission means the particle be a product. Capture or absorption means it will be a reacted. That's the key to this. And then just remembering what's an Alfa particle of beta particle? Positron, a gamma? All those different concepts