ace-master
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#1
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#1
why is the mass of a nucleus less than the mass of the separated protons and neutron from which the nucleus is composed?

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It's because the some of the energy used is converted to mass.

Is my answer right?
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Callicious
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#2
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(Original post by ace-master)
why is the mass of a nucleus less than the mass of the separated protons and neutron from which the nucleus is composed?

Answer
It's because the some of the energy used is converted to mass.

Is my answer right?
If I were an examiner I'd want more elaboration to be honest, you've got to discuss where the energy that would have been this mass has gone, or discuss the mass defect and binding energy, that sort of thing. That's what I reckon at the least.
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ace-master
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#3
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(Original post by Callicious)
If I were an examiner I'd want more elaboration to be honest, you've got to discuss where the energy that would have been this mass has gone, or discuss the mass defect and binding energy, that sort of thing. That's what I reckon at the least.
would this be better?

some of the energy (mass) be used to overcome the strong nuclear force that is trying to hold them together. After the fission reaction the binding energy per nucleon increases so the nuclei is more stable now. and the mass defect woud be equal to the mass of the constituents - the mass of the nucleus.
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Callicious
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(Original post by ace-master)
would this be better?

some of the energy (mass) be used to overcome the strong nuclear force that is trying to hold them together. After the fission reaction the binding energy per nucleon increases so the nuclei is more stable now. and the mass defect woud be equal to the mass of the constituents - the mass of the nucleus.
With respect to your first question, I reckon the top sentence is great, however you're focusing on fission and not including fusion! Fusion also increases the binding energy per nucleon in general.

During binding work must be done to overcome the strong nuclear forces of the atomic constituents, alongside the electrostatic repulsion due to these constituents, and this work is equivalent to the binding energy.

That's the phrasing straight from the repository that is my head. For the reasoning behind why the mass defect increases...

During fission and/or fusion, the binding energy per nucleon increases, and this results in more energy released when the atomic constituents form the new nuclei, resulting in a higher energy required to split the new nuclei, and hence resulting in a larger mass defect for the products involved.

There's some other phrasing. That's just the physics behind it though, you'd need to form that in to the answer you desire.
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Cerdic
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#5
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(Original post by ace-master)
why is the mass of a nucleus less than the mass of the separated protons and neutron from which the nucleus is composed?

Answer
It's because the some of the energy used is converted to mass.

Is my answer right?
This should be the opposite way round. The individual particles have more mass which is converted to energy.
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Mortyyy
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#6
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In order to separate one nuclei to two, you have to do work on the particle to overcome the strong nuclear forces. This means energy is put into the nuclei, and in accordance to E=mc^2, there must be a change in mass. If energy is absorbed by the nuclei, there will be an increase in mass. This means that the two new nuclei have a larger mass than the original nuclei.

In terms of binding energy, Uranium will have a higher binding energy than Tellurium, Zirconium and 4 neutrons. This means when Uranium splits, energy is released, and this released energy means there's a change in mass (E=mc^2) known as the mass defect.
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