What is Mass defect: Definition and 42 Discussions
Nuclear binding energy is the minimum energy that is required to disassemble the nucleus of an atom into its constituent protons and neutrons, known collectively as nucleons. The binding energy is always a positive number, as the nucleus must gain energy for the nucleons to move apart from each other. Nucleons attracted to each other by the strong nuclear force.
The mass of an atomic nucleus is less than the sum of the individual masses of the free constituent protons and neutrons. The difference in mass can be calculated by the Einstein equation, E=mc2, where E is the nuclear binding energy, c is the speed of light, and m is the difference in mass, This 'missing mass' is known as the mass defect, and represents the energy that was released when the nucleus was formed.The term "nuclear binding energy" may also refer to the energy balance in processes in which the nucleus splits into fragments composed of more than one nucleon. If new binding energy is available when light nuclei fuse (nuclear fusion), or when heavy nuclei split (nuclear fission), either process can result in release of this binding energy. This energy may be made available as nuclear energy and can be used to produce electricity, as in nuclear power, or in a nuclear weapon. When a large nucleus splits into pieces, excess energy is emitted as gamma rays and the kinetic energy of various ejected particles (nuclear fission products).
These nuclear binding energies and forces are on the order of one million times greater than the electron binding energies of light atoms like hydrogen.
Consider the equation
X (200, 50) + n (1, 0) -> Y (120, 30) + Z (70, 20) + 11 n(1, 0)
Let p be the mass of a proton, n be the mass of a neutron.
BE(X) = [50p + 150n - M(X)] c^2
BE(Y) = [30p + 90n - M(Y)] c^2
BE(Z) = [20p + 50n - M(Z)]c^2
The energy released when using BE (products) - BE...
Mass – Energy Relationship:
According to Einstein’s special theory of relativity, when the energy of a body increases, so does its mass, and vice versa. If the difference in energy is indicated by ΔE and the difference in mass by Δm, these two quantities are related by his famous equation...
Hi.
I read that the mass of nucleons in nucleus of Oxygen-16 (or nucleus of another atom) is less than the sum of its nucleons if they were separated (also the mass of 8 protons and 8 neutrons).
But why does nucleons have less energy in nucleus of atoms than if they were separated? What causes...
Hello. Can you shed a different light on why mass defects exist please, so that I might finally grasp it intuitively?!
I've had a look at these nuclear threads and one about GPE,
https://www.physicsforums.com/threads/why-is-there-a-mass-defect-in-the-nucleous.374443/...
Hello.
Suppose you were to assemble a sphere of negative charges. When you are done, the rest mass of the sphere is larger than that of the negative charges because they gain energy in forming the sphere. But the invariant mass of the electrons can't change and apparently gaining energy doesn't...
I've just watched a video by PBS spacetime on how an object with more potential energy has more mass, or less, in some cases (mass defect). But there is a problem.
Quantum mechanics tells us that a particle has a chance of appearing at difderent places ( wave function), and that it also...
Hi, I was reading the wiki article here on beta decay and energy release: https://en.wikipedia.org/wiki/Beta_decay#Energy_release
In obtaining a condition on the masses of the initial and final atoms we neglected the difference in electron binding energies of the two atoms. Does this mean we...
I may be misguided here but to my understanding, separate nucleons have a higher mass altogether than the combined nucleus as the potential energy gained from being separated (in the field of the strong force) is being manifested in more mass. If this is true, and if it's not I'd like to know...
Hello,
in nuclear physics we have a mass defect by the binding energy of the nuclides.
A similar effect appears in the theory of gravitation induced by the gravitational binding energy, which reduces the mass.
But for example at the ISCO of an Kerr black hole we have binding energys about...
Hi, this may be a very trivial question but,
When calculating energy, is it BE(products) - BE(reactants) or is it the other way round?
I have been solving questions and the solutions were products - reactants for some and reactants - products for some.
Also for mass defect , is it mass (...
Hello there,
I'm starting S382 astrophysics with the OU. The course book says "The proton-proton chain converts four hydrogen nuclei (protons) into a ^4_2He nucleus, two positrons that quickly collide with electrons and are annihilated, and two neutrinos. Hence, branch I of the p-p chain may be...
What's the mass difference between a hydrogen atom and it's constituent particles when they are free, I'm talking about the proton and the electron, not the quarks that make up the proton.
Homework Statement
The difference between the mass of one oxygen atom and the sum of the masses of its parts is approx. 2.27 x 10^-28 kg. What is the binding energy that holds an oxygen atom together? (The charge on one electron is 1.6x10^-19 C).
Homework Equations
E = mc^2
The Attempt at a...
Homework Statement
Just one more nuclear question if I may,
Homework Equations
None.
The Attempt at a Solution
I can do the first part of this question, but am unsure on the second part. I thought it may be related to the Q-factor (the difference in energy of the initial and final products...
Homework Statement
Americium-244 is a rare isotope of Americium. What is the mass defect of Americium-244?
Use the following values for atomic and neutron masses when calculating your answer:
Homework EquationsThe Attempt at a Solution
This was what I did:
Mass of protons = 95 x...
Hello,
I'm currently writing a chemistry program. The user can create any kind of atom he can imagine, and then combine them into molecules. To properly calculate all the energies involved I need a formula to calculate the mass defect of a nucleus. I mustn't use empirical data to allow for...
Hello. Sorry for being annoying, I've posted like three questions today. But I'm studying nuclear chemistry and still somewhat confused regarding the binding energy and mass defect and their relation with the strong nuclear force..
1) in this Hank Green video...
He says that the mass defect...
I don't know if I completely understand mass defect and binding energy so I will write what I understand and hopefully you can explain any misunderstandings I have.
I know what mass defect is and that I understand that we need the strong nuclear force to keep the nucleus together etc. but I...
Hi!
According to E=mc^2, we have the phenomena mass defect. For example, when we put a proton and neutron together, that particle has a slightly lower mass than the sum of mass of the free particles due to the binding energy between the nucleons. OK, I'm fine with that - a lower energy results...
in high school we are learning about mass defect in nuclear fission and fusion and I know the math: ΔE=Δmc^2
however often the mass changed into energy is much less then the mass of a single nucleon(proton or neutron) and there are no fewer nucleons. for this to happen I would think that you...
This is just a simple conceptual question.
When we try to calculate a nuclear binding energy of some nucleus,
we get the mass defect(del M) and find the binding energy by using
(del M)c^2 right?
Well, what I do not understand is this.
For instance, let's take a formation of a...
In nuclear physics, when two nucleons (e.g. a proton and neutron) fuse together, they release binding energy.
There is a mass discrepancy between the newly formed deuterium nucleus and the initial mass of both nucleons.
This mass defect is related to the binding energy by the famous...
Why is there a mass defect in the nucleus?
I think about mass defect in this way - A comparatively unstable nucleus( i.e. low binding energy) converts to a stabel nucleus( high binding energy)
Intially internal energy was U1 and then it became U2.
So when it converts then some energy...
Homework Statement
Find the mass defect of O-15.
2. The attempt at a solution
I've see a couple different suggested ways for computing the mass defect and I want to know if I'm doing this correctly.
Mass of O-15 = 13,975 MeV/c^2
Proton mass = 938.3 MeV/c^2
Neutron mass = 939.6...
I was wondering how mesons or the strong force is accounted for in mass defect.
Nucleons individually have more mass then when they are bound together in a nucleus of an atom.
I saw a teacher/professor speak on youtube. He said the binding energy (strong force) was calculated as part of the...
Homework Statement
What is the mass defect of the 40Ca nucleus?
Homework Equations
Δm=(Zmp+(A-Z)mn)-m
The Attempt at a Solution
mass of 40Ca=40.078 amu
mass of proton in amu is mp=1.0073 amu
mass of neutron is mn=1.0087 amu
atmomic number of 40Ca is Z=20
its mass number is...
Homework Statement
What is the mass defect of the 7Li nucleus (A = 7)?
Homework Equations
mass of 7Li nucleus per atomic table is 7.016004 u
N = A-Z or #neutrons = 7-3 = 4
computed mass of proton and neutrons in nucleus = 3 p*mass of p + 4n *mass of n
mass of proton = 1.00726 u
mass of...
hello everyone,
following the book of Landau&Lifsitz I managed to understand the Schwarzschild solution.
At the end, it finds this formula for the mass of the spherical body generating the gravitational field:
M=\frac{4\pi}{c^2} \int^a_0 \epsilon(r) r^2 dr
in which \epsilon(r) is...
Homework Statement :
the binding energy for the electron in the ground state of hydrogen-2 is 13.6ev
what is the corresponding mass defect of the hydrogen atom in amu (atomic mass units)
not sure if you need atmoic mass of the hysgrogen atom its given to be 2.014102u
Relevant equations:
not...
Hi,
I was wondering about something in my notes that I don't quite understand. In positive beta decay in nuclear physics, we have a proton becoming a neutron and kicking out a positron and an electron neutrino (which is assumed massless here).
In the expression for the energy released, Q =...
Can someone explain to me why is there a mass defect in the nucleous? That is, why the nucleous' mass is smaller than the sum of the masses of its constituents (nucleons)?
PS. Just to inform you about my background, I am in the 4rth year in physics.
The funny thing is that i was first taught...
I understand that when two nuclei combine to form another nuclei . the resultant nucleon will have a lower mass than the some of the two parent nuclei. I also understand that the missing mass has been given out as energy...
Does this mean that the protons and neutrons have actually gotten...
What is the mass defect of the 15N nucleus?
My attempt:
15-7=8
7(1.008665)+8(1.0078225)-14.003074
=1.120161
the answer needs to be in u so i don't know if this makes a difference or not but for some reason it is not working
Homework Statement
For the common isotope of nitrogen, 14N, calculate the mass defect.
Homework Equations
\DeltaM = Zmp + Nmn - M
The Attempt at a Solution
7(1.00727646688)+7(1.00866491560)-14.003074
\DeltaM = .108516177
Masteringphysics says this is wrong. says i may...
[SOLVED] Nuclear Physics - Mass Defect & Binding Energy
1. Carbon 12 (^{12}_{6}C) has a nuclear mass of 1.99264 x 10-26 kg, a proton has a mass of 1.67353 x 10-27, and a neutron has a mass of 1.67492 x 10-27 kg. Calculate the mass defect for carbon 12.
My equation looks like this...
I'm doing a nuclear chemistry project right now, and I am able to solve all of the problems involving binding energy and mass defect, however I have one conceptual question. Why is it that when the nucleons combine with each other they let off energy? At first I thought it was their kinetic...
1. For astatine 21885At (atomic mass = 218.008684 u) obtain each of the following:
(a) The mass defect in atomic mass units
wrong check mark u
(b) the binding energy (in MeV)
MeV
(c) the binding energy per nucleon (in MeV)
MeV
2. Shown in atempt...
Homework Statement
For lead N=210 Z=82 Pb (atomic mass = 209.984163 u) obtain each of the following:
(a) The mass defect in atomic mass units
u
(b) the binding energy (in MeV)
MeV
(c) the binding energy per nucleon (in MeV)
MeV
Homework Equations
The Attempt at a...
http://en.wikipedia.org/wiki/Binding_energy#Mass_Defect
But the opposite is true for galaxies! Quarks too! Their mass appears to be larger than their constituents as well...