Nucleus Definition and 409 Threads

Looking at the liquid drop model of the nucleus and the semi-empirical formula for the atomic mass of the nucleus. I understand the formula but I'm trying to figure out why some nuclei are unstable against both beta- and beta+ decay. Any ideas? I assume it's something to do with the...

Homework Statement I am wondering about something: Calculate the Fermi energy for the neutrons confined to a nucleus with 40 protons and 50 neutrons which roughly forms a sphere of radius 4.6 10^(-15) m. Homework Equations the formula of the fermi Energy is EF=...

I am wondering about something: Calculate the Fermi energy for the neutrons confined to a nucleus with 40 protons and 50 neutrons which roughly forms a sphere of radius 4.6 10^(-15) m. the formula of the fermi Energy is EF= ((h-bar)^2*(3*pi^2*n)^(2/3))/2m m:mass of electron, n = number...

why doesn't the electron fall into the nucleus!? yes I know this question must have been asked before right? tried looking for it on here but I couldn't find it. the only answer I have gotten to this was just that particles are quantized... yes yes, fine... but WHY? for instance, why does an...

Homework Statement An unknown nucleus contains 71 neutrons and has twice the volume of the nickel http://www.webassign.net/www32/symImages/f/1/3dca243bf11d1adbce4ca198d1973f.gif nucleus. Identify the unknown nucleus. Homework Equations r = (1.2X10^-15)(A^(1/3)) V= (4/3)(pi)(r)^3...

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

Hey I'm new to this forum, just want to say hi! I'm not sure if this is the rite place to put this but sry if i posted in the wrong section >.< I'm actually working on an assignment in my natural science course and I'm stuck on this question cause I'm not sure how to use the variables in the...

I thought that the hydrogen nucleus is just a single proton. So why does this page mention "electorns, protons, hydrogen nuclii", etc? http://blogs.discovermagazine.com/badastronomy/2009/04/07/hot-light-from-a-cold-comet/

was it something that was figured out solely through atom smashers?

A Fe nucleus at rest emits a 14.0-keV photon. Use conservation of energy and momentum to deduce the kinetic energy of the recoiling nucleus in electron volts. (Use Mc2 = 8.60E-9 J for the final state of the Fe nucleus.) what I have so far is... E = pc because E >> photon rest energy , which =...

Homework Statement The nucleus of an atom has a charge of 65 protons. (a) What are the direction and magnitude of the electric field at 4.9 x 10^-10 m from the nucleus? (b) What are the direction and magnitude of the force exerted on an electron located at this distance? Homework...

Homework Statement Estimate the mass of a nucleus with a radius of 2.80 * 10^-15m. Homework Equations I do not know if there is an 'equation' for this. The Attempt at a Solution The answer is 2.11*10^-26.. but I don't even know how to approach this question.

Homework Statement What energy alpha particle would be needed to just reach the surface of an Al nucleus if its radius is 4fm? *This problem is found in a section dealing with Rutherford's gold foil scattering experiment, so take it in that context. Homework Equations F=(kqQ)/r2 The Attempt...

Well I was talking to my physics teacher because were currently studying nuclear physics. And he likes tellign stories to make his examples more straight foreward. And I asked the question what types of radiations are in nucleaar bombs. Gama, Beta or alpha. He answered me with those three types...

Hi: I am confused that we talk in general about only nuclear spin larger than 1/2 which has electric quadrupole. For spin half, there is no quadrupole because of its spherical shape. Anyone can comment on why they are sphere? what is physical significance behind? I read some research articles...

Homework Statement In an elastic collision between a proton and a helium nucleus at rest, the proton was scattered through an angle of 45 degrees. What proportion of its initial energy did it lose? what was the recoil angle of the helium nucleus? Homework Equations...

Homework Statement What is the magnitude of the electric field at a distance of 5.00 ×10−10 m from a radon nucleus? =4.95×1011 N/C What is the magnitude of the force on an electron at that distance? =7.94×10-8 N Now here is where I am getting stuck.. Treating the electron classically...

My professor mentioned that the pauli exclusion principle applies to the nucleus. How exactly is the nucleus quantized (the protons and neutrons), and how do the quantization rules apply to it (such as pauli's, hunds, and so on). Also, is this the reason why we don't observed multiple neutrons...

Hi folks, I have what might be a naive question about the decay of unstable nuclei. I've recently been reading about various decay processes (e.g. beta decay, electron capture etc.). Specifically, I'm wondering if it is ever possible for a stable nucleus (say, carbon-12 or any other...

I think this is where I need to be thinking at a quantum level and not a classical level but i keep thinking if an electron travels at the right heading at an atom it would just crash into the nucleus and since opposites attract they would bond and have a nucleus with an electron sticking to it...

Everybody knows that the nucleus attracts the electron by the Coulomb discovered electric attraction force: F = k / r2, which means the further is the electron from the nucleus r, the weaker is the attraction force. On the other hand, those familiar with the classic radio wave theory know...

what causes the protons inside the atoms nucleus to stay together(next to one another), positive repels positive, therefore they should repel each other,

Homework Statement A nucleus decays into two channels with probabilities 0.62 and 0.38, respectively. Its lifeime is 20 hours. What are the decay rates into each of these channels? Homework Equations If there is only one channel of decay, the decay can be described by the formula...

I am sure it is easy to do, but I just can't seem to figure the question out. It is 4 parts and I got the first 2 parts. If someone can give me the steps with the numbers (already handed in assignment, and got it incorrect), that would be much appreciated. 1. What is the magnitude of the...

Do mitochondria have like tiny nucleus? and if not how do they control their DNA replication and translation... thnx

Is there any way to find the distance between a nucleus and its electrons? If possible, how can you figure out the distance between the nucleus and the electrons of an atom? Specifically, a carbon atom?

hi this is probably basic physics but how do u work out specific charge of say the nucleus of a carbon atom? thanks Marco

Homework Statement A positively charged alpha particle is fired, in a direct line, at a positively charged gold nucleus: o--> O o: alpha, O: golden nucleus. Because of their mutual repulsion, the alpha particle does not actually hit the nuleus: it comes to rest, for a...

Question: In 1997 we celebrated the centenary of JJ Thomson’s discovery of the electron. Thomson pictured the atom as being like a currant bun, with electron ‘currants’ embedded in a positively charged ‘bun’. Give a short account of three ways in which our model of matter on a subatomic scale...

Homework Statement A nucleus that captures a stray neutron [in a nuclear reactor, for example] must bring the neutron to a stop within the diameter of the nucleus by means of the strong force.That force, which "glues" the nucleus together, is approximately zero outside the nucleus. Suppose...

[FONT="Georgia"][SIZE="3"]Homework Statement An alpha particle is emitted from a stationary nucleus at 1.8 \times 10^7 ms^{-1}.The mass of the particle is 4u and that of the nucleus is 212u. (u is a unit of mass equal to 1.66 \times 10^{-27}kg.) (a) Find the recoil velocity of the nucleus. (b)...

If every thing's made up of atoms then that means air's made of atoms too so there can't be air between an atom's nucleus and electron so what is there? Nothing?

is there a reaction called nucleus reaction? my question is can we have reaction that has only the nucleus by separating the electron cloud and why we have in nuclear reaction most of the time reactions have the elecron in it and if we take the nucleus alone there will be no reactions having...

CAN ANYONE HELP ME ? An automatic nucleus initially moving at 500 m/s emits an alpha particle in the direction of its velocity, and the new nucleus shows to 450 m/s. If the alpha particle has a mass of 4.0 u and the original nucleus has a mass of 222 u, what speed does the alpha particle have...

Homework Statement In xenon (Z = 54), what is the effective charge Zeff experienced by an electron in the M (n=3) shell? Homework Equations Zeff = Z - total electrons in K and L shells The Attempt at a Solution I think total electrons in K shell are 8 and in L shell are 18...

How does the binding energy per nucleon of a nucleus affect its stability?

[SOLVED] Gamma radiation gamma radiation does anyone know how it is produced within the nucleus? and I know that gamma radiation takes place after a isotope has undergone a decay and is in an excited state. I know that what interest me is the very nature of the excited state! and how the...

If a free proton is pushed to within 10^-13 centimeters of a nucleus, it overcomes the repulsion interactions and is locked into the nucleus. Is there a known limit to the size of a nucleus? Is there a limit to how many protons we can add to a nucleus? Thanks for your help John

Hi, Why the electrons in an atom doesn't fall into the nucleus? May be because of wave-like building of the electron? Thanks.

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?

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...

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...

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...

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?

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

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...

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

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...

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...

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...