Atom Definition and 999 Threads

Homework Statement In the Bohr model of a hydrogen atom, what is the magnitude of the electric force exerted between the proton and the electron when the electron is in the n = 1 state? Homework Equations E= - 13.6 eV/ n^2 The Attempt at a Solution I simply...

I just have a small question regarding lorentz cavity: Refer to a small lorentz cavity in a uniformly polarised dielectric. as shown in fig. E_{ex}: External electric field. E_{P}: Electric field in the uniformly polarised dielectric (when sphere has NOT been cut out) E_{L}:Electric field...

Homework Statement A hydrogen chloride molecule may be modeled as a hydrogen atom (mass: 1.67 x10^-27 kg ) on a spring; the other end of the spring is attached to a rigid wall (the massive chlorine atom). If the minimum photon energy that will promote this molecule to its first excited...

What happens to the space in two atoms that fuse together? Fusion takes place inside the sun’s core from the protons of two atoms fusing together. Is the new atom bigger or has the space between the nucleuses and the electrons remained the same and some space disappears?

say we had two states \psi1 and \psi2 and i want to model the superposition of the two states \psi=c1\psi1+c2\psi2. how do i find c1 and c2? I've been trying to do c1=\int\psi \psi1 r^2dr over the limits 0 and infinity but i don't seem to be getting anywhere. does anyone have any ideashow i...

hi, if p is a solution of the schrodingers equation for the hydrogen atom then is pt? (where t is the time and p is the known solution) i don't no how to do this due to the complexity of the wavefunction in the first place thanks

Homework Statement In the Bohr model of the hydrogen atom, the speed of the electron is approximately 2.01e6 m/s. Find the central force acting on the electron as it revolves in a circular orbit of radius 4.84e-11 m. Answer in units of N. Homework Equations Fc=m*v^2/R The Attempt...

The physics building is based on the invariance of the atom. Is there any principle or law or experiment ? I think that we only presume. What if there is no foundation for our 'truth' ?

Homework Statement Set up the Schroedinger Wave Equation for Li. Hint: Don’t forget to consider electron-electron interactions. Homework Equations H^\Psi=E\Psi, etc. The Attempt at a Solution I understand how to set up the equation, i.e. how to use the H^ operator, obtain...

From the CNN: http://scitech.blogs.cnn.com/2009/11/06/baguette-toting-bird-stalls-atom-smasher/ I hadn't heard about this except from here. Story: A piece of bread got into some external electronic equipment and caused a problem. It is thought a bird did it. I find it odd that the LHC...

First to tell, I'm a ordinary people who curious in science field. I can't use difficult word myself but I can understand when you use it don't worry. ......... Most of atom is space right? (Nucleus at center and electron cycle around very far away compare to it's size.) Okay, what I...

Below is an excerpt from Quantum Enigma: Physics Encounters Consciousness. I have a few questions following the text. The text goes on to describe that by opening holes in the boxes, the wave function leaks out of both boxes and falls on a screen to which an atom will stick, resulting in...

Homework Statement i have a question that i really need help on! A stable isotope of chromium is 52 Cr 24 Calculate the Charge of the atom!Homework Equations The Attempt at a Solution what i thought is 24x(1.60x10-19) but this gives me the charge of the nucleus! please help!

Q: Why is the 11th electron of the sodium atom located in the third energy level rather than in the second energy level? xD

What is the maximum number of electrons in an atom whose highest-energy electrons have the principal quantum number ? I tried 54 and 110. Neither was correct.

Hello my fellow physic-doers, If say a nucleus containing 2 protons pulls on 2 electrons. Will the electron be pulled closer if the number of protons is constant but there is only one electron assuming there was no repulsion between 2 electrons in the first case? Does the electromagnetic...

Homework Statement A hydrogen atom in its ground state is illuminated with light having a wavelength of 96.7 nm. can the hydrogen atom's electron be excited to a higher energy state by absorbing one of these photons? If so, determine the state and wavelength of any photon that would be...

Okay, since this is just a very small portion of my homework question, I'm not going to use the format provided. I hope this doesn't get deleted! At first, I thought i could just use q in the final answer since I don't know what q is, but what I have is: A polarized molecule with...

Homework Statement For the molecule ICl3 I) How many lone pairs of electrons are on the central atom? II) How many other atoms is the central atom bonded to ? III) What is the molecular geometry of the molecule? IV) What is the electron-pair geometry? a) triangular planar b)...

What is meant by total negative energy associated with bound bodies like planets. and also total energy of the hydrogen atom is negative. I wonder how it could be? Because I believe whatever negative energy may be, It must only be associated with bound systems, and I don't think that an isolated...

Just wondering about photoexcitation of an atom. Say I have an atom that has excitation wavelengths of 500nm, 450nm, and 300nm. If I want to get to the level that is equal to 300nm, do I have to first hit the atom with the 500nm, and 450nm. Or can I just hit the atom with 300nm? Does...

Homework Statement For a object of mass m, Heisenberg’s uncertainty principle relates the uncertainty in the object’s position Δx to the uncertainty in the object’s speed Δv: (Δx)(Δv) ≥ (h divided by (4)(pi)(m)) where h is Planck’s constant. Calculate the minimum uncertainty in the speed...

I have been wondering how an atom is ionized and multiply ionized in an electric field? In a single ionization, does only one electron go through each transition until it is ionized? What about in a multiple ionization? Would the first electron travel through all transitions while the...

Homework Statement Hi all - I've done all but the last part of this problem, for which I have the solution, but I was hoping someone could explain why the solution is what it is :) q:The Hamiltonian of a quantum system suddenly changes by a finite amount. Show that the wavefunction must...

This is not homework, but is not general discussion, so not sure where this would go. In class we were deriving with the radial equations of a hydrogen atom, and in one of the equations was the commutator term: \left[ \frac{d}{d\rho}, \frac{1}{\rho}\right] my attempt was: \left[...

I just have a quick question. Which way of Atom Excitation is more efficient? Photon Energy which matches the absorption peak(s)? Or Photon energy of a Shoter wavelength than the absorbtion Peak?

Homework Statement Using the Feynman-Hellman theorem, determine the expectation values of 1/r and 1/r^2 for the hydrogen atom. Homework Equations Hamiltonian: H=-\frac{\hbar^2}{2m}\frac{d^2}{dr^2}+\frac{\hbar^2}{2m}\frac{l(l+1)}{r^2}-\frac{e^2}{4\pi\epsilon_0}\frac{1}{r} energy...

What is the relative velocity of two hydrogen atoms colliding head on at a temperature of 10 million Kelvin? How do you calculate this?

Hi All, Thermodynamics forbids perpetual motion based in its second law, but how should one deal with an isolated H atom, seen here as a machine? Is there a concrete perspective of its stopping? In its stationary and fundamental state may one observe dissipation? Thank you DaTario

Homework Statement Find the electric potential a distance of .5 x 10^-10 m from the proton of a hydrogen atom Homework Equations V= kQ/r The Attempt at a Solution I know how to answer the question, because I know which equation to use. What I do not understand is, where the...

what is the location of the higgs boson?

This is most likely very simple, but I can't figure it out. http://www.sussex.ac.uk/physics/teaching/btv/Lect02_2006.pdf Step 5 they've got an equation for \Phi. They then normalise it to get A = \frac{1}{\sqrt{2\pi}}. Every time I do the integral I get: A^2.^{2\pi}_{0}[...

Moved. Delete please.

This question is something that's been bothering me for a long time, there has to be a probability in this universe where a single atom is/was floating in space alone without any light exciting it. Clearly there is no heat here, so does the atom approach absolute zero asymptotically? My...

Homework Statement find the magnetic moment of a hydrogen atom given that the election moves at 0.10c around the nucleus and the radius is 0.5*10^-5 m Homework Equations n/a The Attempt at a Solution this is what i did. I = nev =ev (I = current e= charge of electron, v =...

Homework Statement According to classical physics, a charge e moving with an acceleration a radiates at a rate dE/dt = - (e2a2)/(6pi epsilon c3) a) Show that an electron in a classical hydrogen atom spirals into the nucleus at a rate dr/dt = - e4/ (12pi^2 epsilon^2 r^2 me^2c3) b) Find...

I am having a problem with this question in a past exam paper...I may just be being a bit of an idiot: Show that if an H atom is in its ground state the minimum energy photon it can absorb is 1.634x10-18 J. I am using The formula: En2-En1=hcR∞(1/n12 - 1/n22) I keep getting a...

Q. In a particular spectrometer, doubly ionised \stackrel{12}{6}C and singly ionised \stackrel{6}{3}Li atoms are detected. The ratio of the path radii is 1.00252, the Li having the larger value. The fields are constant. Find the mass of of the lithium atom. I can only think of the equation...

Suppose that the electron in the hydrogen atom obeyed classical mechanics rather than quantum mechanics. Why should such a hypothetical atom emit a continuous spectrum rather than the observed line spectrum? So far I have: quantum mechanics deals with the smallest possible piece of a system...

Hey, Sorry, but I have a qustion on the uncertainty principle to join the many others. Just reading a book on physics, and its says that, as a result of the Heisenberg uncertainty principle, if the proton and electron were confined to the same volume of space, the electron would be traveling...

When we solve the hydrogen's atom problem using the Schrodinger equation, we find the eigenstates of energy in the position representation for example. To do that we use the fact that the observables "H, l^2, l_z" have the same eigenstates. My question is about the l_z operator. The z-Axis is a...

As I understand it, a uranium atom should exist in a superposition of its three isotopes (U238,U235,U234). Is this correct? If so, the probability of any isotope being observed should be related to its natural abundance. But this would mean that the probabilities are time dependent, which is...

Homework Statement Heat is added until the rms speed of a helium atom has increased 50%. Find new pressure. (Not all parameters given.) Homework Equations rms = (3kT/m)1/2 mass of molecule = mass of mole/NA Then, mass of helium molecule is 6.6x10-26kg The Attempt at a Solution...

A reactor is producing nuclear energy at the rate of 30000KW.How many atoms of U-235 undergo fission per second?How many kg of U-235 would be used up in 1000 hr of operation.Assume an energy of 200 Mev is released per fission.(Avogadro number=6*10^26 atom/kg)

Homework Statement A photon enters an atom in the ground state. I have the energies to get to the next level. My question is, does the photon have to be the exact energy to get to the next level before it is absorbed, or can the atom absorb it and go up those few levels and.. sort of store the...

Why does in QM the electron does not fall toward the nucleus? After all, the only force between nucleus and electron is attractive. It seems that the electron can and does indeed fall toward the center in <simple harmonic oscillator>? My question is what's so different in these two systems...

Homework Statement the wavelengths of the emission lines produced by the hydrogen atom are given by the formula: 1/lambda = 1.096776 x 10^-2 ((1/n2^2) - (1/n1^2)) nm^-1 (a) what are the wavelengths of the first two lines in the Balmer series, H-alpha and H-beta (involving transitions...

Homework Statement Hi, I am not sure about the following question: (Q) Argon (atomic weight 40) exists as a monatomic gas at room temperature and pressure. The density of liquid argon is 1784kg/m^3. (a) Calculate the atomic density (atoms/m^3) in liquid argon *Done* (b) Hence...

Homework Statement For an electron in a hydrogen atom: in state psi(100): find (del-x)(del-p) where del x = integral of :[psi (x-<x>)2 psi]dv and del p = integral of: [psi(p-<p>)2 psi]dv Homework Equations The Attempt at a Solution i attempted to multiply out both...

Experiments in nuclear magnetic resonance for example, demonstrate that precessing atomic nuclei do it so smoothly. At the same time, atoms have discrete magnetic moments presumably associated with spins. Would anyone care to comment on the difference?