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Questions tagged [binding-energy]

Please use binding energy in the context of the atomic scale and/or atomic systems. This can be used in nuclear reactions.

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Why doesn't a deuterium-deuterium reaction usually yield Helium-4?

I assume the above reaction is less energetically favorable than the creation of He-3 (plus a neutron) or tritium plus a proton? But why/how? Or are the hard, hot, fast collisions too much for it to ...
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Why does fusion above nickel 56 require energy?

I've always struggled with the concept of fission and fusion. I mean I can show a mass deficit with math easily enough but I have always struggled understanding the fundamental concept of why things ...
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Why is the kinetic energy of an electron in a hydrogen atom at $n=2$ level, the negative of its total energy?

My textbook [1] says in order to determine the De Broglie wavelength of an $e^-$ in a hydrogen atom at energy level $n=2$, we can determine its kinetic energy first by finding its total energy from $E=...
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Released energy during fusion reaction

Click to view the video at required time According to the video in the link above the binding energy for deuterium is about 2 MeV and the binding energy for tritium is about 8 MeV so the total for ...
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Why do only heavy radioactive elements perform fission?

Why do only heavy radioactive elements perform fission? I mean what's so special about heavy elements which makes them ideal for nuclear fission? Also why do only neutrons show fission/fusion and why ...
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Binding energy, fission and fusion

My high school physics book doesn't elaborate the idea of binding energy and how it's related to fission and fusion adequately in a way that made me have wrong thoughts about these ideas. What i ...
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Where does energy come from in a nuclear fission if nucleon count doesn't change?

In a nuclear fission the total number of protons and neutrons are conserved. Then the mass converted to energy $E=mc^2$. From where this mass come from? Does that mean that all protons and neutrons ...
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34 views

Binding energy and strong force

If binding energy is responsible for holding nucleons together than what is meaning of strong force?
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54 views

Reaction energy $Q$

Really simple question, but I'm confused with it because of contradictions between sources (absence of clarity online vs lecture notes (says nuclear) and practise questions provided (uses atomic) ) ...
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1answer
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Why is the isotope of lead-206 stable against alpha decay?

The mass of Lead-206 is larger than that of Mercury-202 + Helium-4. Why is then Lead-206 stable against alpha decay? I have heard that the beta-decay can stabilize a nucleus against alpha decay, and ...
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1answer
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Binding energy of a molecular ion?

The protons in the $\text{H}_2^{+}$ molecular ion are $0.106 \, \mathrm{nm}$ apart, and the binding energy of $\text{H}_2^{+}$ is $2.65\,\mathrm{eV} .$ What negative charge must be placed halfway ...
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Binding energy - why is my logic wrong?

We have some protons and neutrons and want to create a nucleus. We must do work against the Coloumb force to bring these protons and neutrons together to form the nucleus, this increases the energy ...
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Why do unstable nuclei form?

Why do unstable nuclei form? Is it that we simply find unstable nuclei in nature and understand what these nuclei do in order to become more stable? I feel like textbooks gloss over this question ...
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Scope of $E=mc^2$ [closed]

As far as I can see, Einstein's $E=mc^2$ is most often mentioned in the context of nuclear physics, even though it is more generally applicable. I understand that this is due to the large nuclear ...
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1answer
43 views

Stability of isotopes

Yesterday I was looking at the semi-empirical mass formula and calculating some binding energies of specific nuclei. Eventually I came across this website that listed both total binding energies per-...
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Limit to number of neutrons in nucleus [duplicate]

As far as I understand the number of protons in a nucleus is limited because Coulomb forces grow faster with the number of protons than the nuclear force. So alpha/cluster decay limits the size in ...
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1answer
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$E = mc^2$ and Binding Energy Confusion [closed]

I have been introduced to $E =mc^2$ and binding energy recently while studying nuclear physics and I have a hard time understanding the following: Mass-Energy what does $E=mc^2$ really mean, as I ...
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0answers
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Isn't it entropy (disorderliness) that every atom in the universe is not of iron Fe?

The concept of mass defect and binding energy Iron has most mass defect and the greatest binding energy. It has the most stable nuclei. Nuclei with higher atomic number than iron undergo fission ...
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Why is the exciton binding energy slightly smaller than the band gap energy?

In a semiconductor it requires energy equivalent to the band gap energy ($E_g$) to excite an electron to the conduction band. This gives rise to an exciton (conduction electron-valence hole pair). The ...
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1answer
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For which kind of nuclear reactions is the nuclear binding energy per nucleon appropriate?

The nuclear binding energy curve is often presented as a reason why iron is abundant in planet cores. However, to me it is not entirely evident why binding energy per nucleon, E/A, is chosen to assess ...
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Bare Critical Masses of $^{241}$Am, $^{242m}$Am, $^{238}$Pu and $^{242}$Pu

$^{238}$Pu has 144 neutrons, and it has 2.8$\times$10$^{3}$ g$^{-1}$.s$^{-1}$ spontaneous fission neutrons and bare critical mass in 10 kg. $^{242}$Pu has 148 neutrons, and it has 1.7$\times$10$^{3}$ ...
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4answers
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How much of the proton's mass is due to the Higgs field?

The proton mass is 938 MeV. People often claim that (A) The proton is a bound state of two up quarks and one down quark, with the three quarks contributing a total rest mass of $2 \times (2.2 \text{...
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Why is the actual KE value smaller than what I calculated?

Problem The nuclear equation for the decay of calcium-47 into scandium-47 is given by: The following data are available: Mass of calcium-47 nucleus = 46.95455 u Mass of scandium-47 nucleus = 46....
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Fusion Kinetic Energy

In fusion, the mass of the reactants is greater than the mass of the products. Thus, mass is lost in fusion. My thinking was that this mass defect is converted into binding energy that is then used to ...
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1answer
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Why do boron 11 and boron 12 isotopes have difference in stability ?(boron 11 is stable and 12 is unstable ) [closed]

Any nucleus will stable if it has neutron number= proton number. Or Even mass number=even atomic number or proton number.(maximum stability ) Or neutron number /proton number less than 1.6(not sure). ...
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762 views

Binding energy converted to kinetic energy/mass loss

My particular question is regarding nuclear fission, but applies to other nuclear processes as well. I understand that in nuclear fission, the two fragment nuclei have a higher binding energy per ...
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0answers
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Why does stability come from binding energy and not mass

The mass of a nucleus is given by: $$ Mc^2=n M_n c^2+zM_pc^2-B(z,n) $$ And we were told that nuclei want to maximise the binding energy per nucleon. However, I don't see why they don't want to ...
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2answers
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Why is the energy taken to free neutrons irrelevant to the energy released in a fission reaction?

Our teacher is currently teaching nuclear physics and I am confused on the process of calculating the energy released in a fission reaction. An example given in class is as follows: Uranium-235 + 1n -...
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1answer
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If binding energy (from mass defect) is essentially the strong nuclear force maintaining the nucleus, why is it released?

I am aware that during nuclear fusion for light elements and nuclear fission for heavy elements, the resultant elements have less mass than the original reacting elements (ie the mass defect) because ...
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3answers
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Are free electrons truly free?

As this diagram shows, energy levels get closer together as they get higher. Is a free electron then truly free? Or is it in such a high (bound) state of energy that the transitions become nearly (but ...
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2answers
64 views

Why is energy released during fission reactions?

If the energy released during a fission reaction is the binding energy then what energy is left to bind the nucleons together? I'm very confused if there's a better explanation on fission I'd ...
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2answers
77 views

What exactly is binding energy?

I've been reading on radioactivity but along the way I got confused, if binding energy is the amount of energy used in holding the nucleus together then why is binding energy also the amount of energy ...
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1answer
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Can I make a box full of molecules weigh more and then weigh less?

Gee I hope this is clear. Say I have a box full of some element. Helium or whatever. If I could break all the nuclei apart the individual protons will have more mass because of the binding energy, ...
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Effect of Compression/Tension on the Rest Mass of an Elastic Solid

If I compress an elastic solid I will strain the material in the direction of the force and therefore do work that is stored as potential energy in the material. The resulting material will have no ...
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2answers
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How is mass of neutron compared with proton when it is inside the nucleus? [closed]

The mass of free neutron is around 0.1% more than the mass of proton. When it is bound inside the nucleus, neutron mass is less compared to its mass in free state. The question is how much mass it ...
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2answers
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Strong force and radioactivity [duplicate]

Why does adding more neutrons to an atom unstabilise it? Won’t adding more neutrons increase the strong force and thus knit the nucleus more tightly? Or is it because it’s being added in a particular ...
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1answer
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About nuclear energy levels

The energy level of a heavy atomic nucleus such as that of uranium, which is related to the zeta function, is determined by taking a discrete value, but cannot it be represented by an equation like an ...
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4answers
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Difference between Mass Number and atomic mass unit (AMU)

I am struggling to understand the difference between Mass Number and atomic mass unit (AMU). I read several posts on this site but still confused. Mass Number seems like a number (i.e. number of ...
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1answer
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Impact of electronic binding energies on mass

According to relativity, the inertial mass of an object that enters into the force equation to get acceleration is given by the total energy in the center of mass rest frame. $$E=Mc^2=\sum_i (m_i c^...
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Why is hydrogen or helium used in nuclear fusion?

I am not a Physics student. Just out of own interest, I'm studying about fission and fusion reactions. Where I found in fusion, the scientist are using either hydrogen isotope or helium-3 as fuel (...
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2answers
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Why are the dineutron and diproton unbound?

It is known that there is no diproton and dineutron nuclei. Does this mean that two protons or neutrons are not actually attracted to each other? Even if the attraction was weak, wouldn't it cause ...
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2answers
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Why is iron the peak of the binding energy curve?

If Nickel-62 and Iron-58 have more binding energy per nucleon than Iron-56 does, then why is iron-56 shown as the peak of the binding energy curve? Also, does adding neutrons always make the atom more ...
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1answer
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Why does the binding energy curve ever decrease?

So the way I understand binding energy is that if I have two nucleons and I let the come together, they’ll decrease their potential energy as they move closer and this will speed them up as they’re ...
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1answer
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Why Don't All Heavy Elements Decay into $^{62}\rm Ni$?

I read the question If we assume that protons don't decay, then will all matter ultimately decay into Iron-56 or into nickel-62?, but I have a different question concerning the decay that has ...
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If we assume that protons don't decay, then will all matter ultimately decay into Iron-56 or into nickel-62?

Wikipedia says that all matter should decay into iron-56. But it also says Nickel-62 is the most stable nucleus. So could this mean that in the far future, everything could (through quantum tunneling)...
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2answers
362 views

exciton binding energy and orbital binding energy

What is the difference between an exciton binding energy and orbital binding energy? I can see no difference between them since when an exciton is created, the electron is excited to the next (or one ...
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0answers
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How does binding energy change as more fermions interact?

The subject is few-body quantum mechanics. Given a system of $N$ identical fermions (spin 1/2) interacting through pairwise potentials $V_{ij}$, how does the binding energy change between $N$ and $N+1$...
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Why do fusion and fission both release energy?

I only have high school physics knowledge, but here is my understanding: Fusion: 2 atoms come together to form a new atom. This process releases the energy keeping them apart, and is very energetic. ...
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185 views

Binding energy per nucleon dependency

For a given isotope, does the nuclear binding energy per nucleon depend on the presence of electrons? For instance, if an electron was excited by an incoming photon and jumps to a different orbital, ...
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1answer
83 views

Stability in Nuclear Shell Model

As far as I understand , a particular sub-shell is filled with either protons or neutrons, $2*(2l+1)$ number of them, and never both together since protons and neutrons fill up levels separately in ...