Nucleus Definition and 409 Threads

When a nucleus is placed inside an external magnetic field, it aligns itself parallel to the field, as that is the most stable position for it to be in. In more technical terms: it acquires an alpha spin. When you shine radio waves at this nucleus, it absorbs energy and flips over anti-parallel...

If I'm scattering electrons off of an atomic nucleus, can I infer any information about the duration of time the electron was accelerating by looking at the wavelength of the emitted bremsstrahlung radiation? I am wondering if it would be possible to derive a time interval between electron...

Homework Statement I want to know why probability disintegration per second of a radioactive nucleus does not depend on time lived by it. Homework Equations N/N(initial)=e^(-λt) The Attempt at a Solution According to the above equation, the probability should increase with the passage of...

I've noticed that in the Shell Model of the nucleus, the order of the energy levels is 1s, 1p3/2, 1p1/2, etc. While in the atomic energy levels it goes 1S 2S 2P, ... But they still take the same amount of particles for each level in both the atomic and nucleus. Am I missing something here? Or...

How electron revolves around orbitals? Is the velocity uniform or accelerated?

The nucleus of the H atom is neutral when it has two electrons and one proton (when forming a covalent bond) or it has one electron and one proton.

Why are higher magic numbers not accurately predicted if nuclear potential is assumed to be a central potential? Nuclei with magic numbers have a higher stability that those without. If we think of the nuclear potential as a central potential though these magic numbers aren't predicted...

What does this diagram tell us about the distribution of nucleons in the nuclei? - The diagram is from Krane Introductory Nuclear Physics I know that nucleons don't congregate around a central part of a nucleus, but instead have a constant distribution throughout. i.e. The number of nucleons...

Need a quick answer!

Consider the pairing term in Weizsäcker formula. Here https://en.wikipedia.org/wiki/Semi-empirical_mass_formula#Pairing_term it is claimed that: I don't understand how Pauli exclusion principle should be the cause of this. This term comes from spin-spin interaction (or "coupling"), but I do not...

Atoms make up all the material stuff around us, but most of an atom is empty space. The nucleus at the centre of an atom (99.95 percent of its mass) is orbited by tiny electrons (only 0.05 percent or less of the overall atomic mass). And as you've probably heard, an analogy is to think of the...

In paragraph 5.7 of this lecture, Feynman explains how to calculate the apparent area of the nucleus, in a sheet of unspecified material. I have two questions about the formula used by Feynman. 1) Although the sheet has a thickness, the formula considers only the superficial area of the sheet...

Homework Statement An alpha particle approaches at high speeds a gold nucleus with a charge of 79e. What is the electric force acting on the alpha particle when it is 2.0e-17 m from the gold nucleus? Homework Equations FE=k(q1q2)/d2 The Attempt at a Solution FE=k(q1q2)/d2...

So I have been learning about measuring nuclei radius using electron diffraction, using sin(theta)=1.22lambda/d, doing some research I found out that is the equation for circular aperture diffraction but I don’t really understand how a group of nucleus can act as a circular aperture. Also is...

My unreliable memory is that although Schrödinger's equation treats the interaction between an electron and the nucleus as unquantised, it is more generally thought to be mediated by an exchange of quanta between electron and nucleus. I want to check on this and get a better understanding. Can...

So we have a nucleus. Let's say its a helium nucleus. If I want to split this nucleus into its constituent nucleons, I must do work against the strong force which is holding it together. Now that I have done the work, the particles are no longer bound. I have done work against the strong force...

Homework Statement How to calculate the Coulomb barrier between a proton and a lithium nucleus. The variable is r (interaction radius). The known data is Z1, Z2, k (Coulomb constant), and e (elementary charge). Homework Equations The equation is UCoul = kZ1Z2e2/r The Attempt at a Solution I...

Homework Statement Homework EquationsThe Attempt at a Solution Since energy of photon is very low compared to the rest mass energy of the nucleus, I consider non – relativistic calculation. Conservation of linear momentum gives : momentum of nucleus = momentum of photon = p...(1)...

As far as I'm aware, pair production always involves the initial energetic photon interacting with another body (e.g. nucleus) to conserve momentum when creating the matter/antimatter products (e.g. electron and positron). Although "secondary" high-energy photons (e.g. ## e^+ + e^- \rightarrow...

Granted, the size difference between a hydrogen atom's electron cloud and its nucleus is a factor of one million (~1Å vs ~10^-6Å), but that's still a significant amount of overlap that, I would think, would trigger the occasional interaction.

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...

So I was wondering why do nucleons need to remove mass to form a nucleus. Is it because it lowers the energy of the nucleus making it more stable or something completely different. I understand that it is the energy input to break the nucleus into its components, however, why do nuclear reaction...

Homework Statement The component of nucleus' energy due to the strong interaction (with ##Z,A >>1##) can be written as ##U_f = E_f A^r Z^p##, (##E_f## is a constant with the dimension of a energy). Find ##r,p## knowing that (i) strong interaction doesn't distinguish between protons and...

Why there is the term ##\frac{3}{5}## in the formula of the electrostatic potential of a nucleus $$U_e = \frac{3}{5} \cdot \frac{(Ze)^2}{4 \pi \epsilon_0 R}$$

Does anyone know the heuristic derivation of this formula? $$R=r_{0} \cdot A^{\frac{1}{3}}$$ with ##R## the atomic nucleus, ##r_0## the radius of a nucleon (proton or neutron) and ##A## the number of nucleons. I know that there is a sperimental derivation, but I would find a theoretic/heuristic...

The first light atomic nucleus with a second face Physicist found the first light atomic nucleus in a lab that had too little resources. http://sciencefeeds.weebly.com/journal/the-first-light-atomic-nucleus-with-a-second-face

For electron scattering experiment which measures charge radius of the nucleus, it's said that energies of scattering electrons (or protons) must be such that their wavelength size is of the same order as nuclear dimensions. While i understand why this must be true I'm not entirely sure. My...

I thought only strange particles were produced in pairs via the strong interaction, however in my textbook it states 'kaons, like pions are produced in pairs via the strong interaction'. Can particles that are not strange also be produced in this way?

Homework Statement The mass of a helium-4 atom is 6.64648310224 g, and each of its two electrons has a mass of 9.10939310228 g. What fraction of this atom’s mass is contributed by its nucleus? Homework Equations fraction of mass = mass of nucleus/mass of atom The Attempt at a Solution I...

Homework Statement The Q-value of alpha decay of Pu-239 is 5.244 MeV. Calculate the energy of the alpha particle in MeV. Calculate the energy of the recoil nucleus decay product in MeV. (answer correct to 3 decimal places) Homework Equations The Q value of a nuclear reaction is the difference...

Hello, interested, if the posibility of splitting atoms by using resonance is possible, if so, wheather or not I can use it for something else, thanks in advance.

Hi Friends! We know that nucleus of neurons remains like a closed blueprint!Is there any evolutionary pressure for cells not to multiply? Also in hippocampus they can multiply in only a highly limited number.Why different behaviour in hippocampus? Thanks in advance!

The mass of the nucleus is calculated as follows: mass (nucleus) = [Number of protons * Mass of proton] + [Number of Neutrons * mass of neutron] - [Binding energy/c^2] Why is the contribution to mass from the binding energy subtracted from the mass of the nucleus rather than being added to...

Homework Statement Derive following expression for the electrostatic potential energy of an electron in the field of a finite nucleus of charge, ##+Ze##, and radius, ##R=r_0A^{1/3}##, where ##r_0## is a constant. (Charge density is constant.) The potential we are asked to derive is: $$ V(r) =...

Homework Statement I am to calculate the density of a nucleus, say, of Iron, with mass 55.845 amu. Homework Equations see below The Attempt at a Solution I come to notice that all elements have the same value for the volume if I use the formula: $$mass=m=m_{amu}(1.66\times10^{-27}kg/1u)$$...

Tony Stark: I've tried every element. Nick Furry: You haven't tried all of them. Are there any other particles besides protons and neutrons (and their antis) that could be stable in the nucleus of an atom?

Homework Statement An alpha-particle with velocity 3.5 x 106 strikes a block of gold, atomic number 79 and mass number 197. Find the distance of the closest possible approach between the alpha particle and a gold nucelus, assuming Coulomb's law holds over such distances. Assume mp = mn = 1.67 x...

Has anyone ever tried to tally the complete energy associated with an atomic nucleus. For example, here is a partial list: Total electric repulsion of protons within a nucleus Total kinetic energy of protons with a nucleus Total color-charge potential energy within a nucleus Kinetic energy due...

The energy associated with the mass of a free proton in the center of momentum frame where the proton’s momentum is zero is 938.272 (with more decimals). What is the rest energy of a single proton inside a Uranium atom? (It could be any other radioactive or fissionable element but I took...

Hi, A cat cannot be alive and dead at the same time. Is it possible for particles in a nucleus to be both protons and neutrons at the same time? How could you tell whether this is happening?

Homework Statement I want to derive the following equation. It is the potential energy of an electron inside a nucleus assumed to be a uniformly charged sphere of R.Homework Equations V'(r) =( -Ze2/4∏ε0R)(3/2 - (1/2)(r/R)^2) The Attempt at a Solution I get E = Ze2r/(4∏ε0R3) But I am having...

Radioactive things radiate alpha, beta and gamma particles to achieve stability. As nucleus also emits these particles, can we say nucleus is unstable?

Hi Everybody, I've seen that one of the reasons that elements past 137 can't be created is because any element past 137 would require electrons in inner orbitals to go faster than the speed of light, and past 137 they would have to. I have also heard that electrons don't literally orbit the...

Homework Statement What potential difference is needed to give a helium nucleus (Q = 3.2 × 10-19 C) 50 keV of kinetic energy? Homework Equations V=U/Q 3.2 × 10-19 C = 2e The Attempt at a Solution I was quite sure I had the right answer but it keeps saying I'm wrong? V = (50*10^3 eV) / 2e =...

Various sources describe the origin of the eukaryotes as occurring when a bacterial cell ingested an archaea cell, which then symbiotically became the nucleus of the created cell, and which was then the LUCA (Latest Universal Common Ancestor) of all the eukaryotes. The cell membranes of the...

Hello everyone, If a nucleus consisting solely of mesons has enough mesons in it, will it be stable? Mesons are bosons, therefore (unlike baryons) they aren't effected by the pauli exclusion principle, so they all can acquire the lowest energy state. In theory, if there are enough mesons, the...

Homework Statement An example of a weak decay of a nucleus is (Z, A) → (Z +1, A) + τ- + ντ-bar where (Z,A) represents a nucleus with Z protons and A−Z neutrons. (d) Suppose the gauge boson in the above process is produced at rest. Assuming the neutrino is massless, what must the 3-momenta of...

Using electrical potential energy =1/4πεo Q1Q2/r , a particle further away from nucleus has lower magnitude of energy Using coulomb's law, a particle further away from nucleus experiences weaker attraction, hence less energy is needed to maintain orbit* around that e-shell compared to a...

Using electrical potential energy =1/4πεo Q1Q2/r , a particle further away from nucleus has lower magnitude of energy Using coulomb's law, a particle further away from nucleus experiences weaker attraction, hence less energy is needed to maintain orbit* around that e-shell compared to a...

I have read about gluons and pions, but I really don't understand what mediates the binding between the proton and neutron and how it happens! Can you also explain this?