Nucleus Definition and 423 Threads

  1. R

    Mean radius, r.m.s. radius of nucleus

    Hello, Given a particular charge distribution p(r) = p_0*exp(-r^{2}/a^{2}), I was wondering if the proper way to calculate the mean radius <r> would be \intp(r)*r*p(r) dV ? Which would make <r^{2}>^{1/2} = (\intp(r)*r^{2}*p(r) dV)^{1/2}, correct?
  2. Q

    How Much Total Kinetic Energy Do Split Nucleus Fragments Have?

    Homework Statement 6. A nucleus of mass Mo=222.0 u at rest spontaneously splits into two equal fragments, each of mass M=110 u. When these two fragments are far apart, how much total kinetic energy do they have? That is, what is the sum of their individual kinetic energies? (Note that 1...
  3. T

    Can the Uncertainty Principle Prove Electrons Cannot Be Inside the Nucleus?

    Homework Statement It is given the maximum energy of electrons emitted in beta decay. I'm asked to show using that and the uncertainty principle that electrons cannot be inside the nucleus. Homework Equations The Attempt at a Solution I can't show my work because I don't even...
  4. malawi_glenn

    Is the Moment of Inertia Formula for a Fluid Nucleus Accurate?

    Hi! I was wondering if some here can confirm this formula given by K.S Krane in his book "Introductory Nuclear Physics", page 145, eq # 5.19 \mathscr{I} _{\text{fluid}} = \dfrac{9}{8\pi}MR^2_{avg}\beta (5.19) Moment of inertia for a ellipsodial fluid. Where \beta is the deformation...
  5. G

    Excitation levels and Nucleus Size

    How would you use excitation levels (or the lowest excitation level) to find the radius of a nucleus? And how would it differ to using the r=r0A^(1/3) formula?
  6. G

    How is the Moment of Inertia of a Nucleus Calculated in Various Excited States?

    Homework Statement The unstable Tungsten isotope: ^{174}_{74}W has various excited states. The spin parity J^{P} and energy levels of some of these states are given below in the table. Show that this series of states is generated by rotational motion in the nucleus and calculate moment of...
  7. N

    Calculating Binding Energy & Forming Deuteron Nucleus

    How can the time of binding energy be calculated?If so how long does it take to form deuteron nucleus?
  8. W

    Electron-Nucleus Interaction: Magnitude and Motion

    Homework Statement 1) What is the magnitude of the electric field at a distance of 3.30 ×10−10 m from a thorium nucleus? 2)What is the magnitude of the force on an electron at that distance? 3)Treating the electron classically, that is, as a point object that can move around the nucleus at...
  9. K

    Orbitals around the nucleus problem

    Rsepected sir Please read my doubts in the attachment and kindly answer it. Thankyou.
  10. X

    Electron Inside the Nucleus on Helium Atoms Problem

    Homework Statement Quantum mechanics makes the electrons-in-the-nucleus theory untenable (for example on helium nucleus where before they know that a neutron exist, they thought that it was composed of four protons and 2 electrons). A confined electron is a standing wave, whose wavelength in...
  11. T

    Spontaneous fission condition of the nucleus

    As we know the spontaneous fission of an odd nucleus to an 2 odd nuclei happens with high probability when (Z^2)/A is greater than or equals 45 The conclusion of this is attached in pdf file with the post using the liquid drop nucleus model to explain the problem The question is here now...
  12. Amith2006

    What Is the Maximum Speed of the Daughter Nucleus in Negative Beta Decay?

    Homework Statement 1)Determine the maximum possible speed of the daughter nucleus in negative beta decay of a He(6,2) nucleus which is initially at rest. Homework Equations The Attempt at a Solution I solved in the following way: He(6,2) --> Li(6,3) + electron + antineutrino...
  13. D

    Why Is a Neutron Stable in a Nucleus but Unstable When Free?

    A (free) neutron has a lifetime of some 10 minutes or so, how come it is stable in a nucleus?
  14. M

    Closest Approach of Alpha Particle & Gold Nucleus

    In Rutherford's scattering experiments, alpha particles (charge = +2e) were fired at a gold foil. Consider an alpha particle with an initial kinetic energy K heading directly for the nucleus of a gold atom (charge = +79e). The alpha particle will come to rest when all its initial kinetic energy...
  15. C

    Why Does the Electron Not Fall Toward the Nucleus in QM?

    Why does in QM the electron does not fall toward the nucleus? After all, the only force between nucleus and electron is attractive (- electron and + nucleus). Is the same reason that justifies the moon does not fall to the earth?
  16. A

    Total energy of an excited nucleus?

    If a nucleus is in its first excited state, is its total rest energy then mc^2 + Eex1?
  17. A

    What is the Shell Model Interpretation of Low-Lying Levels of C-13?

    Homework Statement The low-lying levels of C-13 are ground state, \frac{1^-}{2}; 3,09 MeV, \frac{1^+}{2}; 3,68 MeV, \frac{3^-}{2}; 3,85 MeV, \frac{5^+}{2}. Interpret these four states according to the shell model. Homework Equations Negative parity --> \ell = odd; the valence nucleon must...
  18. S

    Nucleus having only neutrons ?

    Can we have a nucleus containing neutrons alone? Thanks in advance.
  19. R

    New Book: Models of Atomic Nucleus (2006)

    I recently purchased a new book that reviews most historical models of the atomic nucleus: http://www.brownstationers.com/BookItem.aspx?item=9783540285694 This is the only book on this subject in the past 40+ years that gives positive review (well--any review actually) for the 1965 Linus...
  20. N

    Exploring Electron Motion Around the Nucleus

    Hey people, I have beeno wondering this for a while: If the nucleus of an atom is positively charged and the electrons are negatively charged, why don't the electrons stick to the nucleus like a magnet, why do they only have a certain distance between themselves. If the electrons are...
  21. T

    Electric Force Acting on Alpha Particle and Gold Nucleus

    Homework Statement an alpha particle (charge=+2.0e) is sent at high speed toward a gold nuclues Charge= +79e. What is the electrical force acting on the alpha particle when it is 2.0 times 10^ -14m away from the gold nucleus Homework Equations The Attempt at a Solution its 91 N...
  22. I

    High energy electron scattering and proof of nucleus structure

    Hey all, I am currently revising for my Physics mock but i can't get my head around high energy electron scattering, and the proof this provides for the size of the nucleus. I have read from a variety of texts and some of the links on here but these have lead me to become even more...
  23. M

    Calculating the Density of a Uranium Nucleus

    this seems like a fairly simple problem, however I'm not sure if my calculation seems right... the question: The nucleus of a uranium atom has a diameter of 1.5 * 10 to the -14 and a mass of 4.0 * 10 to the -25. It then asks what the density of the nucleus is. I know that nucleus...
  24. V

    Explaining the Nucleus: Positive Charges & Observations

    Can you tell me the answer to this question? Why would the scientific community resist the concept of a nucleus full of positive charges and what observations helped them explain this design. Thanks, v
  25. P

    Calculating Charge of Radon Nucleus

    Hi, this problem is killing me. What is the total charge of the radon nucleus? (The neutral radon atom has 86 electrons.) The units is in Coulombs so I figured since they were asking for the charge of just the nucleus then it would be 86 protons times -1.6x10^-19 C. But that didn't work...
  26. P

    Charge of Radon Nucleus: 86 Protons -1.6x10^-19 C

    Hi, this problem is killing me. What is the total charge of the radon nucleus? (The neutral radon atom has 86 electrons.) The units is in Coulombs so I figured since they were asking for the charge of just the nucleus then it would be 86 protons times -1.6x10^-19 C. But that didn't work...
  27. Amith2006

    Stability of nucleus on emission of elementary particles

    # It is said that atoms of elements of high atomic mass are unstable. So they emit alpha, beta or gamma rays. Suppose an atom emits alpha rays. The binding energy of alpha particle is about 27 MeV(million electron volt). It is said that as a result of this emission, the binding energy per...
  28. T

    Nucleus of an atom contains only neutrons and protons?

    thanks hootenanny:wink: im not sure if my teacher had set this question wrongly or not? because I am finding it hard to answer. the question goes: TWO statement below are INCORRECT. which are these 2 statements? A.) the nucleus of an atom contains only neutrons and protons. B.)The...
  29. L

    Calculating the radius of a nucleus of a Pd-118 atom

    Here is the question I am attempting to solve : A proton or neutron has a radius r of roughly 110-15 m, and a nucleus is a tightly packed collection of nucleons. Therefore the volume of the nucleus, (4/3)R3, is approximately equal to the volume of one nucleon, (4/3)r3, times the number N of...
  30. J

    Strong nuclear force and Iron nucleus

    While reading the book " Cosmic Catastrophes. Supernovae, Gamma-Ray Bursts and Adventures in Hyperspace" by J.Craig Wheeler I came across this line: "By the happenstance of the nature of the strong nuclear force among protons and neutrons, the fifty-six particles of an iron nucleus are more...
  31. R

    Triton Nucleus & C14: Radiogenic Properties & Instability

    To all: In some detail what makes the tritium isotope of hydrogen radiogenic? And since C12 and C13 are both stable what makes C14 unstable? Thanks Rieman Zeta
  32. T

    The Deuterium Nucleus Spin Question

    Ok, I have a question that's really irritating me. I am trying to explain why deuterium's nucleus has a spin of 1. By the addition of angular mometum of the individual nucleons (1 proton and 1 neutron) that make up the deuterium nucleus, there are three possible choices (from the triangle...
  33. 4

    The atom is how many times larger in volume than its nucleus?

    I am new to physics, so bear with as I don't know a lot yet. I was given this problem to figure out, but have been having a difficult time. A hydrogen atom has a diameter of approximately 1.06*10-10 m, as defined by the diameter of the spherical electron cloud around the nucleus. The...
  34. P

    Finding the electron increases if we go towards the nucleus?

    Is it true that the probability of finding the electron (s-electron) increases if we go towards the nucleus? then what accounts for its stability from not being attracted by the nucleus n collapsing into it..its a basic question but i don't have an idea now! Is it just the concept of constant...
  35. P

    Explanation why dosen't the electron fall into the nucleus?

    Since the nucleus of an atom is +charged and the electron is -charged, why doesn't at least one electron fall into the nucleus?
  36. G

    Can the nucleus of an atom have an overall “neutral charge”

    Can the nucleus of an atom have an overall “neutral charge” if there happens to be more neutrons in the nucleus than protons?
  37. L

    Magnitude of the recoil velocity of the nucleus

    The nucleus of 214Po decays radioactively by emitting an alpha particle (mass 6.65*10^-27) with kinetic energy 1.23*10^-12 J, as measured in the laboratory reference frame. Assuming that the Po was initially at rest in this frame, find the magnitude of the recoil velocity of the nucleus that...
  38. S

    Rutherford Scattering problem with a heavier nucleus

    An alpha particle approaches a Au (gold) nucleus with atomic mass number 197 with a speed of 1.5*10^7 m/s. The alpha particle is then scattered 49 degrees from the horizontal at the slower speed of 1.47*10^7 m/s. In what direction does the Au nucleus recoil below the x-axis (the horizontal)...
  39. J

    Virtual Photon Lifetime: Proton in Atom Nucleus

    QFT states that all forces are due to the exchange of virtual particles, I'm interested in photons and their role in the EM force. I was wondering what the maximum time allowed for existence of an exchange photon is when it's emmitted from a proton in the nucleus of an atom. I'm thinkin' that...
  40. D

    Why Do Electrons Closer to Nucleus Have Less Energy?

    Some one please make me understand why electrons closer to the nucleus have less energy than the ones which are farther from it. Is it because they have more potential energy? Secondly, How do we know that protons exist as particles but not as a ball of positive charge. Thanks in advance for...
  41. S

    Understanding the Charge on the Nucleus

    I've got this following question which I don't really get: What is the charge on the nucleus of each of the following? (assuming they are neutral) a) Mg b) Ne c) K^+ d) S^2- What I don't understand is the definition of "charge on the nucleus" I am assuming that only protons...
  42. Loren Booda

    Electron band structure in a nucleus

    Consider a nucleus with N neutrons and Z protons. Can one justify it alternatively as a nucleus with N + Z protons and N electrons, the latter occupying orbitals either confined to the nucleus or following beta decay according to their electronic potential?
  43. DaTario

    Field of an accelerated electron falling down to nucleus versus photon

    Assuming the electron is orbiting (semiclassical approach) the nucleus at the second allowed distance from it (2s, for example in H). When the electron decays (classical electrodynamics) it probably will do it in a kind of spiral trajectory. This trajectory implies acceleration and so, a...
  44. ZapperZ

    Undergrad Physics & Astronomy Resource: The Nucleus

    As part of the ComPADRE Digital Library, the Nucleus is a resource for undergraduates in Physics and Astronomy. It has discussion forums, textbook reviews, online lessons by subjects, summer research openings, etc. Currently, they are highlighting the translation of Einstein's Special...
  45. M

    How Is Kinetic Energy Distributed in a Thorium to Radon Decay Process?

    A 232 Th (thorium) nucleus at rest decays to a 228 Ra (radon) nucleus with the emission of an alpha particle. The total kinetic energy of the decay fragments is 6.54 x 10^-3 J. An alpha particle has 1.76% of the mass of a 228 Ra nucleus. a) Calculate the kinetic energy of the recoiling 228 Ra...
  46. S

    Question regarding radius of circular paths (chapter the nucleus)

    I have my doubt,solution and question in the attachment that followed.Thanks for anybody that spend some time on this question.
  47. F

    Energy to remove a proton and a neutron from a nucleus

    Hey guys, I know this is basic nuclear physics but I've forgotten how to do it. Given the atomic mass of Oxygen 16 (8p 8n), Oxygen 15(7n 8p) and Nitrogen 15(8n 7p), having found the average energy binding energy per nucleon (i think i have it right) find how much energy is required to remove...
  48. D

    Electrons & Nucleus: Spinning & Value?

    Do the electrons spin around the nuclues? If so, do we know the value?
  49. J

    Joe's Uranium Problem: Alpha Particle Emission & Final Nucleus Mass

    Here I have a problem: A 232/92 Uranium nucleus emits an alpha particle with kinetic energy=5.32MeV. What is the final nucleus and what is the approximate mass(in units) of the final atom. I can write the equation for the reaction, this will give 4/2 He and 228/90 Th. If the alpha particle...
  50. R

    Atomic Spin: Origin in Nucleus & Impact of Electrons

    Is the spin of an atom come from (or based on) the Nucleus (i.e. net of Neutrons and Protons)? With the spin of the Electrons not really noticed or counted though a sense of being ‘lost’ or masked by being in an orbital?
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