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In this video, we are going to write the nuclear equations for the decay process of thorium -232 until we get to the stable isotopes.
00:07
So they give us each step.
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So we're going to write that equation step by step, balancing them in mass and charge.
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So we have thorium -232, that's th, and we'll look at the periodic table to get the atomic number, which is 90.
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And we're told that the decay is alpha decay.
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So we have a helium nucleus plus the other product.
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Now, the top numbers have to add and the bottom numbers have to add.
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This is a 90.
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So 232 is equal to 4 plus 228, and 90 is equal to 2 plus 88.
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So our product is something with an atomic number of 88.
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That's got the periodic table.
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8045, 86.
00:49
Where is 88? oh, radon.
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Radon 228.
00:56
All right.
00:57
Next we have a series of two beta decays.
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We have to do them one by one.
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So we have first, it's going to be a loss of an electron.
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I'll do the beta symbol.
01:12
So the mass number stays the same, and then the atomic number is going to go up by one.
01:18
Right? so 88 equals negative 1 plus 89.
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And then we look at the periodic table to get this is going to be actinium.
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And then we do the same thing.
01:28
Actinium 228, 89, emits a beta particle, mass number stays the same.
01:37
Atomic number goes up by one, and then we're at thorium again, thorium -228.
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All right.
01:47
So that's alpha -beta -beta.
01:48
Now we have four alpha decays in a row.
01:59
So we'll just put the four alpha decays here, and then we'll fill in the blanks.
02:12
All right? so we know that the mass number has to go down by four.
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So this is going to be 224, and the atomic number goes down by two.
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So this is 88...