Nucleus Definition and 423 Threads

Homework Statement How does a large DNA molecule enclosed in the nucleus of a cell? The Attempt at a Solution I know it has to do with histones and how DNA winds twice around it to make it shorter, but can anyone further expand on this? Thanks : )

Homework Statement {a} Calculate the average binding enrgy per nucleon in the deutrium nucleus {b} The energy that binds an orbiting electron to the hydrogen nucleus is 13.4 eV. Calculate the ratio of the binding energy per nucleon to the binding energy per electron in deutrium. Which...

why according to classical, electron circuling around the nucleus will emit EM wave and lose energy and collapse? I know electron undergoes circular acceleration, but why emit EM wave?

I'd like to consider a primordial black hole in the absence of Hawking radiation. When you consider the case of a primordial black hole with a Schwarzschild radius on the same order as the radius of a proton, I calculate its mass to be at around 6.75x10^11 Kg. If I then calculate the...

Hi, I have a question regarding the types of decay and the time of decay for an atomic nucleus. Do all nuclei have a set decay time and method, (by method I mean Alpha, Beta, Gamma decay). i.e. does Uranium only decay via beta decay over a set time? Or can an nucleus decay by any of the...

Hi, I had a previous post "Total Energies" asking about the total energy of an electron and proton separately in a "stable," ground state, hydrogen atom and I got no response (well one short one). Later I realized an isolated hydrogen atom is not stable; it at least needs to bond into H2, but...

Positive electrical charges attract negative electrical charges. The protons in nucleuses (or nucleii? if that's how it's spelled) have positive electrical charges. Electrons have negative electrical charges. So why don't electrons stick to the protons in a nucleus instead of orbitting...

where can I get information about the excitation levels (gamma ray spectrum) of a single proton nucleus?

How do we compute the energy of the ground state using nuclear shell model?

Hi I'm looking for a good description (high-school to 1st year level) why the ratio of protons to neutrons matters for stability. Single neutrons are unstable, but in a nucleus they are stable and the more nucleons you have the greater the strong force. So why can't you have stable isotopes...

I have next to zero knowledge about nuclear physics but after giving some thought to the dynamics of the electron cloud in the atom and its kinetic energy I realized that the motion of the nucleons in the atom is not so frequently discussed and I was wondering ,for instance, in the case of the...

Homework Statement The oxygen nucleus 16O has a radius of 2.91 fm. With what speed must a proton be fired toward an oxygen nucleus to have a turning point 1.11 fm from the surface? Homework Equations Kinetic energy = 1/2 mv^2 Potential energy = 1/4(pi)Enot * q/radius min The...

hi, I am wondering why even numbers of protons, or neutrons, or electrons, are more stable that odd numbers? i have read this on wikipedia: http://en.wikipedia.org/wiki/Oddo-Harkins_rule " In elements with even atomic numbers, protons are paired, with each member of the pair...

an unstable neutron decays to electron, proton and anti neutrino. if that being the case, why electrons are not inside the nucleus?

We stay in orbit around the sun? Our own planet's kinetic energy keeps it from succumbing to the Sun's gravity, same concept with the electrons, this time Gravity being electromagnetic force right? Edit: Damnit, wrong section...

Can a nucleus in an atom emit visible light . I am aware that the nucleus has discrete energy levels, And it seems that they only emit gamma rays, but could we make them emit visible photons. I have just begun to study very basic nuclear physics in my classes. And i am taking EM theory...

Question: If we assume that an electron is bound to the nucleus (assume a H atom) in a circular orbit, then the Coulomb force is equal to the centripetal force: mv^2/r= ke^2/r^2 In the Bohr hypothesis, angular momentum, L = mvr is...

Why do electrons have more energy the further they are from the nucleus?

Homework Statement A proton is fired at a nucleus containing Z protons and N neutrons, with a kinetic energy K. Show that the minimal distance r_0 = [(Ze^2) / 4pi*epsilon_0] * (1/K) Homework Equations E=(q/4pi*epsilon_0) * (r-r' / |r-r'|^3) The Attempt at a Solution I know that at...

Earlier today I was thinking about what is in between the very few molecules of hydrogen floating around in interstellar space (dark matter?), and a question came to me. What is in the space between the nucleus of an atom and the electrons that surround that nucleus? The space would be too...

Why nucleus is spherical in shape in its stable state?

what i mean is could it be possible for an alpha particle to acquire energy (by collision or from emission) and subsequently emit a gamma ray?? or does only have one (ground) state??

While solving the Schrodinger equation for Hydrogen atom, we use the reduced mass and get the wave functions of the electron. I like to get the wave functions of the nucleus as well as that of the electron. This may probably need to avoid using the reduced mass concept. Is this problem...

hello, does the mean lifetime of a decaying nucleus changes with temperature? I generally think that mean lifetime of a given nucleus doesn't change with temperature. thanks for your valuable input.

How do we determine the values of any given fission reaction? How do we answer questions like: A decrease in mass of 3.48x10(to the power of -28) kg occurs. Express the energy equivalent of this in terms of joules and MeV. I keep reading and reading but can't understand. I search online...

Homework Statement We suppose the nucleon density of a spherical nucleus where r<R1 is constant, and where R1<r<R2 the density linearly decreases to 0 at R2. We call the surface nucleons (Number Ns) the number of nucleons contained in the volume R1<r<R2 and core nucleons (Nc) the number...

Homework Statement An alpha particle is bombarded on 14 N. As a result a 17 O nucleus is formed, and a particle is emitted. This particle is a: (a) neutron (b) proton...

1. Predict the minumum speed of a 20.0MeV proton as it passes within 1.0x10^-13 meters of a lead nucleus having 82 protons. (Note: 1eV = 1.6x10^-19 Joules) 2. How do I start off? 3. All i can think of is to get a charge for the lead nucleus by using q=ne which is the number of...

Homework Statement The binding energy of a nucleus is given by: E_{b}=a_{1}A-a_{2}A^{\frac{2}{3}}-a_{3}Z^{2}A^{-\frac{1}{3}}-a_{4}\left(Z-\frac{A}{2}\right)^{2}A^{-1}\pm a_{5}A^{-\frac{1}{2}} For a given set of isobars, A constant, E_{b} will be maximised at the value of Z that satisfies...

Homework Statement 1. Write down an approximate expression for the mass of a nucleus in terms of mass number A and nucleon mass m_{n} 2. Assuming that the nucleus is spherical, find an expression for the volume of this nucleus in terms of A and r_{0} 3. Find a numerical value for the...

1. The predictions of Rutherford's scattering formula failed to correspond with experimental data when the energy of the incoming alpha particles exceeded 32MeV. This can be explained by the fact that the predictions of the formula apply when the only force involved is the electromagnetic force...

if anybody tell me is the of hydrogen and carbons nucleus is same or not.please explane it deaply

Is the space between the electron shell and nucleus a perfect vacuum?

Is a dust nucleus, dust attached to air? If water vapor molecules, attach themselves to dust nucleus in building visible [to the eye] snowflake, I'm supposing flake takes on shape of the dust. Does this mean "air" is shaped too? Don't laugh; I'm most confused!

"neutron collides elastically with a helium nucleus" Homework Statement A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to rebound at an angle θ'2 = 40° from the neutron's initial...

Homework Statement At what distance from a carbon nucleus is the electric potential 2.1 V? Carbon atoms have 6 electrons in the atomic shell. Homework Equations v= K Q / r^2 OR K Q / r (NOT SURE) The Attempt at a Solution use voltage potential for point charge Using either v= K Q / r^2...

Homework Statement A hydrogen atom has a diameter of approximately 1.06x10^-10 m, as defined by the diameter of the spherical electron cloud around the nucleus. The hydrogen nucleus has a diameter of approximately 2.40x10^-15 m. (a) For a scale model, represent the diameter of the hydrogen...

1. Homework Statement What is the different between nucleus and nuclide? Homework Equations N/A The Attempt at a Solution Initially, i think that they mean the same things but now i know it isn't so i am seeking for answer

In an atomic nucleus, there is protons, and neutrons. The protons are positively charged and the repel each other. However, there is an "opposing" that helps to keep the nucleus in a piece instead of breaking apart. Does anyone know what kind of force is this? And what causes this force to be...

Hi, I have a couple of questions about the spin of an atomic nucleus. Say I had a carbon-12 nucleus, which is 6 protons and 6 neutrons. The Pauli exclusion principle tells us that these should be arranged in shells determined by their orbital angular momenta and spins. So, the shell...

Hello, I'd appreciate feedback on my calculation of binding energy, just wanted to check if I'm on the right track w/ regards to calculation steps (and thought process). I'll try to be as clear as possible, please give me input if there's some notations / steps I should correct and keep...

Is an atom's nucleus a single particle? Take for example the nucleus of a lithium atom which contains three protons and three neutrons. Do the wavefunctions of these three protons and three neutrons merge together to form a single particle, in the case of the lithium's nucleus, a...

Homework Statement The nucleus of a zinc atom has 30 protons and 35 neutrons, and a diameter of 4.00 x 10^-13 m. What is the minimum repulsive electrostatic force between two protons in the nucleus. Homework Equations The Attempt at a Solution Not sure how to approach this. I...

Homework Statement A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to rebound at an angle θ'2 = 41° from the neutron's initial direction. The neutron's initial speed is 6.2 x10^5 m/s...

as depicted in the diagram below the stress strain for an alloy with an average nucleus size of 100 micron find 1)the modulus of elasticity for the alloy 2) the yielding stress for 1) i assume that the red line is meant to be at 0.0005 therefore E=dσ/dε=100e6/0.0005 E=200Gpa...

The nuclear electric quadrupole moment is a parameter which describes the effective shape of the ellipsoid of nuclear charge distribution. A non-zero quadrupole moment Q indicates that the charge distribution is not spherically symmetric. By convention, the value of Q is taken to be positive if...

Homework Statement An atomic nucleus is in an excited state. It decays to its ground state with the emission of a gamma ray having energy, Egamma = 24.0 keV. The nucleus has a mass of 9.53e-26 kg. What is the recoil speed of the nucleus? (Note: This may be an inelastic collision)Homework...

A while back I recall reading an article regarding artificially forcing electron particle waves into the surrounding nucleus of an Atom and that the result would shrink the size of the atom. Can an Atom hold more than the normal amount of electrons, if so is there a maximum?

What is an isoscalar nucleus? I guess it should be a nucleus with isospin T=0. In the place where I encountered it, it seems to refer to a nucleus with equal number of neutrons and protons. An isoscalar target should necessarily have equal number of neutrons and protons. But as far as I...