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this mass defect question (1 Viewer)

akkjen

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i thought the answer was D, but it's A. explanation please. thanks
a-1.png
 

Jig

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The Uranium nucleus are split, so the total mass decreases because the Uranium has decayed and used energy to decay to Thorium and Helium. As for total binding energy, one way to think about it is that the nucleus of the Uranium is relatively unstable, so it has somewhat of a low binding energy. So once it decays into Thorium and Helium, they become more stable, which means it would take more energy to split those nuclei again thus having an increased binding energy. I'm not 100% sure though
 

psmao

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uranium is an unstable element so it tends to decay into two more stable elements. The mass is defected into binding energy. Therefore there is an increment in binding energy and decrement in mass.
 

akkjen

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uranium is an unstable element so it tends to decay into two more stable elements. The mass is defected into binding energy. Therefore there is an increment in binding energy and decrement in mass.
why would it do that? if the element is splitting then the total binding energy is decreasing because binding energy is not required anymore to keep the atoms together as one particle. also the mass of the split particles is greater than the mass of the one particle because some of the mass is used as binding energy. SO I DONT undertstand why it is A someone please clear it up thanks!!!!
 

Jig

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why would it do that? if the element is splitting then the total binding energy is decreasing because binding energy is not required anymore to keep the atoms together as one particle. also the mass of the split particles is greater than the mass of the one particle because some of the mass is used as binding energy. SO I DONT undertstand why it is A someone please clear it up thanks!!!!
Uranium has some binding energy whatever it is, but this nucleus will be relatively unstable so we can imagine that the binding energy is not so high to begin with anyway. It does say "Total Binding Energy" so when the Uranium splits into the Thorium and Helium, it has now become more stable, thus the Total binding energy has increase (this binding energy would come from the released mass as I explain ahead, i think). Now as for the mass, the Uranium will have a mass to begin with, and as it splits it just wouldn't make sense for more mass to appear. As the Uranium nucleus splits, this is fission so energy will be released and thus mass decreases (mass-energy equivalence).
 

akkjen

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Uranium has some binding energy whatever it is, but this nucleus will be relatively unstable so we can imagine that the binding energy is not so high to begin with anyway. It does say "Total Binding Energy" so when the Uranium splits into the Thorium and Helium, it has now become more stable, thus the Total binding energy has increase (this binding energy would come from the released mass as I explain ahead, i think). Now as for the mass, the Uranium will have a mass to begin with, and as it splits it just wouldn't make sense for more mass to appear. As the Uranium nucleus splits, this is fission so energy will be released and thus mass decreases (mass-energy equivalence).
thanks!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
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Arrowshaft

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Since the daughter nuclides are more stable, the SUM of both of their binding energy must be greater than uranium’s, as the only reason it underwent radioactive decay was to become more stable, thus have a stronger net binding.
 

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