Atom Definition and 999 Threads

Just a quick question regarding the solution of the hydrogen atom: is it possible to solve the hydrogen atom problem via creation and annihilation operators as is the case with the harmonic oscillator? Any help here greatly appreciated! Crawf.

hi does anybody of you know if there is an equation that describes an atom in a gravitational field of a star or something like that (general relativity or Newton)or do you know some results that could tell me something about the magnitude of this energy corrections? do you know a method...

I was deriving Bohr model formulas and I stumbled upon a problem. When I use the postulate that says that you can apply Newtonian Mechanics to orbiting electron, I wrote the Coulomb's force as following: Fc=(-e)*Z*e/(4pi(epsilon0)*r^2) Minus from the electron means that the force...

Hello! I'm preparing for my quantum mechanics test. In the solutions of an old test I find this conversion, that I don't understand. \Psi = Nze^{-r/2a_0} = Nre^{-r/2a_0}cos\Theta N is the normalization constant, which is to be calculated. I would have guessed that z is the atomic...

Hi there! I don't know if this is the right place but I wanted to know and learn from someone the difference between an atom and a sub-atom. H2O's molecule consists of 1 oxygen atom and 2 hydrogen atoms, right, but what do people mean when they mention "at subatomic levels"? Are sub-atoms what...

I have a question about the stability of positronium. Positronium consists of an electron and a positron whereas hydrogen consists of an electron and a proton. The energy levels of positronium, ignoring fine structure, are -6.8eV/n2 whereas those for hydrogen are -13.6eV/n2. My question...

Homework Statement A helium atom had two electrons in the first shell (1s). Explain, withour detailed derivation, what the value of the total spin quantum number is. Homework Equations ? The Attempt at a Solution Since the 2 electrons are in the first (1s) shell they must have...

1. Hello, I have some questions on my homework which are not so clear. The professor asked for " since the binding energy of the D-μ(it is muon) is much bigger than that of ordinary deuterium atom De, explain what will happen if a beam of muons is directed through a gas of ordinary De atoms...

Hi, I was wondering if the bound solutions to the radial part of the hydrogen atom form a complete set for the functions in L^2(0,\infty). I know that the laguerre polynomials are complete and that they only differ from the radial solutions by factors of x^l * exp, so I thought that they would...

As I understand it, "nonradiative decay" of a system from an excited state to a lower-energy state is any type of decay that does not result in the emission of an electron. I can't think of any way that a free atom could decay without emitting a photon. Molecules, yes, (through...

Hey, probably a stupid question but I can't seem to find an answer anywhere. Is a hydrogen free radical just a single hydrogen atom? A hydrogen atom has an unpaired electron bound right? Thanks in advance

Hi guys, Just got a question I'm a little stuck on and would love a push in the right direction Q) Using Hartree's theory calculate the degeneracy of the ground state of the Sodium atom. Its a previous exam question and I'm struggling to find much descriptive information about the topic...

Homework Statement An electron of know KE collides with a hydrogen atom in its ground state. With what possible KE may it rebound? KE = 11.5 eV 2. The attempt at a solution I assumed that the electron may either hit an orbiting electron and excite him (maximum layer is n = 2, change in KE...

hi i asked myself, is it correct to use the ordinary partition function and cut it off at some value to describe the atom at some finite temperature? or is there a better way to do this calculation? and if i evaluate the partition function for let me say n=2. does this mean, that the...

I haven't posted any of my working for this as I only want to check my answer. Q. For a hydrogen atom with n=2, l=1, m=0 calculate <r^2> My answer = 0.75 * a^2 where a is the bhor radius. Am I right?

Homework Statement I need to calculate the probability distribution of 1s and 2p state of hydrogen atom in momentum and in coordinate representations. I have calculated the wave function in coordinate representation, and the dilemma is, do I simply do the Fourier transform for given wave...

Homework Statement Define the quantum numbers required to specify the state of an electron in hydrogen. The spatial part of the wave-function describing a particular hydrogen atom has no angular dependence. Give the values of all the angular momentum quantum numbers for the electron...

it is obvious that the hamiltonian of an atom is time reversal invariant but how can an atom have non-zero magnetic moment?

Hydrogen Atom ---> Uncertainty Principle Hey guys, I'm having some trouble with this one. [PLAIN]http://img849.imageshack.us/img849/2039/physhw.jpg How do I get started?

If the proton in the nucleus of, say a hydrogen atom, exerts an attractive force on an electron that is in orbit, why doesn't the electron move towards the proton? And does this have anything to do with the electric force being the centripetal force?

I can think of two things. Stimulated Emission and Absorption. Would it be possible to do an experiment where you could control coniditions to allow just these two outomes? Thanks

Also, when an atom emits light when another particle hits it, why does one of the electrons move to the outer shell?

I'm dealing with this problem for an MCAT review: Following beta-emission by a neutral atom at rest, the respective linear momentums of the beta(-) particle and the resulting atom are shown below. (see attachment for message) It wasn't too difficult to see that an extra force is in play, and...

I have confused myself with this by reading a combination of Wikipedia, books and my QM notes and I'm afraid I need someone to untangle me please. Basically what I want to know is, what are the consequences of the Pauli exclusion principle for the ground state of the helium atom? Here's my...

Ok so my problem is I have absolutely no idea where to start. I have been able to figure out other problems but this I can't get my head around. I am unsure as to the equations I need to use for collisions and how to obtain the correct answer. Homework Statement A nuclear reactor (see...

Explain how an atom may have a permanent magnetic dipole moment? Many thanks...

Consider a hydrogen atom whose wave function is at t=0 is the following superposition of energy eigenfunctions nlm(r) (r, t=0) = *[2100(r) -3200(r) +322(r) What is the probability of finding the system in the ground state (100? in the state (200)? in the state (322)? In another energy...

Consider a hydrogen atom whose wave function is at t=0 is the following superposition of energy eigenfunctions \psinlm(r) \Psi(r, t=0) = \frac{1}{\sqrt{14}} *[2\psi100(r) -3\psi200(r) +\psi322(r) What is the probability of finding the system in the ground state (100? in the state (200)? in...

Homework Statement A K shell electron is ejected from a tungsten atom. The result of this is the emission of a characteristic x-ray proton. (The binding energy of the K shell in tungsten is 69.5keV. The binding energy of the L shell in a tungsten atoms is 10.5 keV). a) If the vacancy in the K...

The question is: Which species has exactly five pairs of electrons around the central atom? (A) ClF5 (B) SF4 (C) SF5– (D) XeF4 The answer is B. Can someone explain why? I'm not too good with these geometries that use the d-orbital.

Homework Statement Physicists use laser beams to create an "atom trap" in which atoms are confined within a spherical region of space with a diameter of about 1 mm. The scientists have been able to cool the atoms in an atom trap to a temperature of approximately 1 nK, which is extremely close...

Hi, I've some doubt about quanistic physicist (aren't homework I read this stuff as an hobby) , could you help me? 1)if the electrons of a gas, for example, emit energy only when they go down level, then to get the atomic spectrum should I first give energy and then wait until electrons go...

Non-relativistic QM. I have read in many places that the fourth power of the momentum operator (P^4) is not hermitian on the L=0 states of the Hydrigen atom. Indeed, I was able to pove this using Fnlm for the nlm state of hydrogen, computing <Fn00 | P^4 Fm00> and doing the integration by...

When acceleration reach to the point of speed of light, we know that space will collapse(3D) and time will slow down(relative) does this leads to the creation of atom? Will space collapse to a single point if time is take away? I view the space(3dimension) as a sphere in which time(relative)...

Hello, I just finished learning how to solve the Schrodinger equation for the H atom and a few things trouble me. 1) The relative particle, CoM particle treatment: From what I understand, we are solving this for the case where the nucleus is taken to have mass m1+m2 and the electron has mass...

Homework Statement A pion is a spin-0 particle with a negative unit charge. A neutron is a spin-1/2 particle with no charge. A proton is a spin-1/2 particle with positive unit charge. One can construct an unstable version of the hydrogen atom where the nucleus contains both a proton and a...

Homework Statement A 21 cm spectral line corresponds to the flipping of the electron in a hydrogen atom from having its spin parallel to the spin of the proton to having it anti-parallel. Find the internal magnetic field experienced by the electron in the hydrogen atom. Homework Equations...

1. Consider Bohr Hydrogen atom with counter-clockwise electron orbit in the xy plane with intial position r(0)=-a0y. The angular frequency of the orbit is w. Derive an expression for the position of electron at a later time t, r(t) in terms of a0 , w, t, x, and y. Homework Equations...

(1) Is there any equation to determine how many neutrons there should be to keep an atom stable? I don't mean mass - number of protons. I mean the equation that can determine an interval of neutrons based on atomic number only and the forces. (2)Why can't there be an hydrogen atom with 6...

I've heard that the hydrogen atom that we originally learn about in QM that deals with the Coulomb force is an incomplete description. I'm having trouble understanding all of these effects. When describing the electron energy of the real Hydrogen atom, how do things like the zeeman effect...

Hi everyone, How can I solve hydrogen atom with discrete nonlinear schrödinger equation? Could you help me with the mathematics of that, please?

Homework Statement "Relativistic effects are rather small in the hydrogen atom, but not so in higher-Z atoms. Estimate at what value of Z relativistic effects might alter energies by about a percent and whether it applies equally to all orbiting electrons or to some more than others. For this...

Homework Statement The nucleus of a lead atom has a charge of 82 protons a. what are the direction and magnitude of the electric field at 1.0x10^-10 m from the nucleus? Homework Equations E=Kq/r^2The Attempt at a Solution I did E= ((9 x10^9)(1.6X10^-19)^82)/ (1.0x10^-10)^2 but when I...

Hi. I'm a 3rd year undergraduate studying Applied Physics and I'm having some trouble with a problem concerning the Hydrogen Atom. This is my first post so please forgive the sloppy equations. Not really used to writing this stuff out without an equation editor handy! Anyway, the...

Homework Statement Fe3(Co)x, Fe is 33.26% by mass. Find the value of x. The Attempt at a Solution 167.5425 g / 0.3326 = x ( 58.9326 g) / 0.6628 x = 5.6... but the right answer given was x=12. question...

Hi! Today we discussed atomic physics in our class, and the following question came up: Consider an atom, and consider for example its three lowest energy states. Suppose these correspong to the energies E1,E2 and E3, respectively. Will it be possible for an electron in the lowest energy state...

On my notes, the lecturer left out some of the formulae as blanks which we were supposed to fill in as we went a long but I'm missing a few of them. The 1st one is: [PLAIN]http://img213.imageshack.us/img213/6627/screenshotdh.png I'm stuck here, I can't figure out what equation he's...

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...

Homework Statement Helium is used to fill a balloon of diameter 44 cm at 22 degrees C and 0.9 atm. The mass of a helium atom is 4.0026 u, the conversion factor from u to kg is 1.66 x 10^-27 kg/u, the conversion factor from atm to Pa is 1.013 X 10^5 Pa/atm, the universal gas constant is...

Homework Statement A neutron moving with a speed v makes a head-on collision with a hydrogen atom in ground state kept at rest. Find the minimum kinetic energy of the neutron, for which inelastic collision may take place. Mass of neutron = Mass of Hydrogen = 1.67 x 10-27kgThe Attempt at a...