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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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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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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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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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Molar masses are all wrong! [closed]

I just realised that the molar masses we use in chemistry are all wrong , so every exersice I have solved in chemistry which includes molar masses are all wrong . Hydrogen atom doesnt have the 1/12 ...
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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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1answer
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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
40 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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1answer
61 views

$E = mc^2$ 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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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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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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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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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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1answer
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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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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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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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39 views

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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2answers
48 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
76 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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1answer
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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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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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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
74 views

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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1answer
75 views

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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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
104 views

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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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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1answer
80 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 ...
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1answer
116 views

Binding Energy and mass defect

Binding energy is the energy required to separate the nucleus into its constituent particles. The thing is that I read in a book that the binding energy is also the energy equal to the mass defect. ...
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211 views

Why does a star die once it has iron?

I found out that iron is the death element for stars, but I couldn't find why can anyone knowledgeable on stars explain why iron causes the star to die?
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Is this equation for mass defect correct? [duplicate]

I just want to know if this equation for the mass defect is correct $$\Delta m = Z * m_p + Z * m_e + N* m_n - A $$ where Z- Atomic number A- Mass number N- number of neutrons $m_p$- mass of the ...
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1answer
108 views

Do we know what causes the release of energy in nuclear fission?

I was trying to put together all the things I've read in the last couple of days and I realized that based on my current knowledge of the standard model and the way nuclear fission works, I'm not able ...
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2answers
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What is more massive, Proton, standard Hydrogen?

If you consider the classical states of hydrogen, one in which the electron is rotating at an orbital distance of $r$ and then take $\lim_{r\to\infty}$ one obtains that the $r_\infty$ state has more ...
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1answer
56 views

What is the binding energy between conduction band and valence band of metals and insulators?

As far as my understanding of solid state physics goes, I can't see a clear connection between binding energy and band gap. But our teacher asked us the question as an assignment but i really can't ...
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2answers
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Accurate Equation for Earth's Gravitational Binding Energy

This is a relatively important question for anyone who can answer it. I am trying to find the equation that accurately solves for Earth's Gravitational Binding Energy. The information below is from ...
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2answers
69 views

Binding Energy and Energy Mass Equivalence

Consider a neutral atom. An external force acts on one of its valence electron so that it brings this valence electron to infinity away from the rest of the atom. The electron's kinetic energy does ...
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1answer
62 views

Relationship between binding energy of atoms in a solid and compressibility defined by bulk modulus

Consider an atom which has η nearest neighbours. The equilibrium binding energy $L_0$ of $N$ atoms is: $$ L_0 = \frac{Nηϵ}{2} $$ The bulk modulus $K$ of a solid of volume $V$ compressed under pressure ...
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2answers
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How fast do nuclei need to be traveling when colliding for them to break apart? [closed]

I don't mean fission or fusion reactions with uranium or such. I mean gold or lead or even hydrogen collisions, such as in these particle colliders or outer space, wherein the nuclei seem to touch, ...
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1answer
40 views

Binding energy of the nucleus

In a reaction U235+1n->141 Ba +92Kr +(3) 1n+200MeV, the energy released (200Mev) is of one atom or of 6.023*10^23 atoms?
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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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1answer
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A question about Helium spectrum

I'm starting to read about two-electron atoms from physics of atoms and molecules by Bransden. Analyzing Helium spectrum I noticed that the energy of $He^+(1s)+e^-$ is greater than the energy of He, ...
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4answers
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How exactly does nuclear reactor work in generating energy, when the energy created from fission transformed into binding energy?

I asked this question because I'm a bit confused about the concept of binding energy. From my understanding, in a nuclear reactor, Uranium-235 atoms are bombarded with neutrons so that fission ...
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2answers
102 views

What is the relationship between binding energy / mass number as a function of mass number?

Specifically, in this figure, which shows the binding energy per nucleon of β-stable nuclei, what is the main contribution to the increasing value of B/A at low values of A? And what is the main cause ...