Atom Definition and 999 Threads

Homework Statement Hi, my question is regardng a Coulomb model of an H atom specified with Hamiltonian operator, Hhat, by spherical coordinates of energy eigenfunction ψ2,1,-1 (r,θ, ∅) =(1/ 64∏a02)1/2 r/a0 e-r/2a0 sinθ e-iθ Principal quantum numer n = 2 orbital an mom l = 1 magnetic...

I know temperature is the measure of how much atoms are moving, so can a single atom even have a temperature? The quarks inside the protons and neutrons are moving around, so?

http://img577.imageshack.us/img577/2892/3kow.png both NH3 and SO2 and NH4+ have hybridization sp3

Consider 2 atomic orbitals with wave function a: σ(r), b: μ(r) in a diatomic molecules. σ(r) (or μ(r)) is localized around an atom a (or b) and is relevant for the discussion of the molecular orbital. These orbitals are orthogonal and normalised. The creation operators are x, y and vacuum, |0>...

Homework Statement The question is to find the total angular momentum of the following atoms in their ground state - Na (11 electrons), and Rb (37 electrons). That's all the info given. Homework Equations I have no idea - that's what I can't find! The Attempt at a Solution I've...

I have a couple of questions about selection rules for the hydrogen atom. When we talk about these rules in an undergraduate context we are usually assuming LS coupling where we ignore spin orbit coupling so orbital and spin angular momentum are essentially independent. Is that correct...

Consider the following. You have an electron of negative charge orbiting a proton of positive charge at some distance R (i.e. a classical hydrogen atom). I understand the hydrogen atom is unstable under classical physics because the accelerating electron loses its kinetic energy as...

Homework Statement • Consider a hydrogen atom in its ground level, placed in a magnetic field of 0.7 T along the z axis. (a) What is the energy difference between the spin-up and spin-down states? (b) An experimenter wants to excite the atom from the lower to the upper state by sending in...

1. Consider doubly ionized Lithium (Li++), which has one electron orbiting a +3 charge nucleus. Assuming the electron is in the ground state (n=1), what is the maximum wavelength of light, λ, that would completely ionize the Li++? (free the electron from the nucleus), all variables and...

Homework Statement If an electron and proton (both initially at rest and far apart) come together to form a hydrogen atom, 13.6 eV of energy is released (mostly as light). By how much does the mass of an H atom differ from the sum of the electron and proton masses? What is the...

Hi Everybody, I am currently battling with the fourth and final question of my A Level physics work for this week. The problem has been driving me crazy, as I seemed to have completed all of the relevant steps, and I find the right answer only with negative exponents, which isn’t much help at...

what will happen TO THE ATOM if electron end up inside the nucleus ( as in quantum tunnelling) ?

I'm had this class yesterday that I did'nt understand anything, I have exam on two days and I started to study by myself about potential energy so, I found this equation: Ue(r) = q1 q2/4πε0r + repulsive energy (same as van der Waals) where q1 = -q2 and each q = + or - 1.6E-19 C and...

A stationary hydrogen atom with a mass of 1.67 x10^-27 kg absorbs a photon of light with an energy of 10.2eV.What is the velocity of the hydrogen atom after absorbing the photon? This is my question: Is it true that the atom has no speed since all the energy is completely absorbed at the...

Typically (in popular literature) the process of photon emission by an excited atom is considered as an instant event. But actually it is quite likely that it is a continuous process. Such processes are usually described by evolutionary differential equations (ODEs or PDEs). Assume that we...

I just read the thread entitled: "How did Einstein Define Time" and I'm very confused. At school, I was taught that time was an abstract representation of movement meaning that the word "time" can only be used to represent movements. For example, when Earth has completed a cycle around the...

If we have a moving, neutral atom, say hydrogen, will it react to a magnetic field? If yes, why? If you ask why not, I argue that the atom as a whole is a chargeless entity.

Let us assume there is a single atom in a vacuum chamber which is kept at near absolute zero. Now assume the system is closed and that the chamber is large enough such that the atom cannot diffuse far enough to reach the walls. Neglecting other stochastic effects, what do you think the atom's...

I am wondering about acceleration in quantum mechanics. Let's consider spherically symmetric potential V(r). From the Heisenberg equation of motion, one finds the time derivative of the momentum operator \dot{\hat{p}}=\frac{i}{\hbar}\left[\hat{H},\hat{p}\right] = -\nabla V, from which we can...

I realize atoms are held together by STRONG electromagnetism, but if you were to convert this energy into an everyday scenario, how strong would it really be? I'm trying to explain the power behind a small atom and I feel using a 'real', known object. Thank you in advance for any answers.

Homework Statement Hydrogen is in n=2, l=1, and m=0. Wave function is ψ(r,θ,∅)=(1/4(√2pi)ab3/2)(r/ab)(e-r/2ab)(cos(θ) Find <r> for this state. Homework Equations P(r) = 4pir2|R(r)|2 <r> is equal to the integral from 0 to ∞ of P(r)dr The Attempt at a Solution I understand...

Homework Statement Calculate the uncertainty product ΔrΔp for the 1s electron of a hydrogen-like atom with atomic number Z. (Hint: Use <p> = 0 by symmetry and deduce <p^2> from the average kinetic energy) Homework Equations All I have is the wavefunction. For a 1s, it takes the form...

Do hydrogen atoms have inner and outer electron shells? I saw a diagram somewhere that showed a carbon atom with an inner and outer shell, is this proven? Are these shells magnetic or something else? Do you consider the outside of these shells as the diameter of the atom?

When you solving Sroedinger eq for hydrogen atom you get energy values ##E_n\approx \frac{1}{n^2}##. Why for some value of this energy electron don't leave atom?

Homework Statement I am wondering how for determine the central atom's orbitals from the point group character tables described by group theory. For example CO3^-2 (D3h) Carbon's (central atom) p-orbitals are described by a1''+e'. The s-orbital is a1' Homework Equations The...

Homework Statement How do you find the contributions per atom for calculating the reducible parts? For example CO3-2 has pt. grp: D3h. From the character tables-- the first row (unshifted atoms) is: 3,0,1,3,0,1. Second row (coefficients): 1,2,3,1,2,3 Third Row (contributions per atom)...

IBM's "A Boy And His Atom: The World's Smallest Movie" https://www.youtube.com/watch?v=oSCX78-8-q0 ...how it was made www.research.ibm.com/articles/madewithatoms.shtml

Homework Statement The ground state of the hydrogen atom has the wavefunction: \psi (r) = \frac{1}{\sqrt{\pi}} (\frac{1}{a_{0}})^{\frac{3}{2}} e^{-r/a_{0}}, where a_{0} = 0.53Å a) Calculate the probability that an electron will be found inside the nucleus of the hydrogen atom, which is...

Homework Statement Individual hydrogen atoms have been prepared in the energy state n = 2. However, nothing is known about the remaining quantum numbers. Fine structure and all corrections can be ignored. What is the micro-canonical statistical operator. Homework Equations \hat{\rho_{mc}} =...

Hi, I am a graphics programmer / animator and would like to play around and try to visualize an atom. I think I can do better than the run of the mill spheres or blobs as they are normally portrayed. I have a decent physics background, I know QED by Richard Feynman by heart, and I have...

Ultra cold atom is achieved by laser cooling. For optical lattice, it is achieved by the interference of counter-propagating laser beams. What is the relation between Ultra-cold atom and optical lattice? Why do people load Ultra-cold atom in optical lattice? Thank you for your answer.

Normally, Oxygen has 8 electrons in its neutral form that is 1s2 2s2 2p4. In this case, its principal quantum number (n) is two. But what happens if it got excited and its electronic configuration becomes 1s2 2s2 2p3 3s1? In this case, Is the principal quantum number (n) of oxygen two or...

Hello PF members, I am trying to solve for helium atom ground state by using perturbation theory. It is very easy to calculate the first order correction of ground state energy but I have no idea for how to find its wave function. I have tried to use the first order correction formula for wave...

Homework Statement The energies of some transitions observed in the absorption spectrum of an unknown one electron ion ( eg He+) are listed. Given that these transitions originate from the lowest energy level suggest an identification of the unknown ion UNKNOWN ION (CM^-1) 1646254.1...

Homework Statement A hypothetical atom is diatomic containing two identical atoms separated by an equilibrium distance. About this distance the atoms vibrate with the electric forces providing an effective spring constant of k = 4.0×10^−3 N/m. As the temperature of the sample is increased the...

Homework Statement Suppose that there is an isolated chlorine atom and there is an isolated electron in its surroundings. Then what force will act on the electron to pull it towards the atom. Homework Equations The Attempt at a Solution I know that chlorine will attract the...

Hi! I have some trouble with atomic unit. I have a laser pulse with the wavelength of ##800 nm## at the peak intensity of ##1.0*10^{14} W/cm^{2}##. I'd like to calculate the corresponding electric field ##E_0##. I use the formula ##I=0.5Cε_0{E_{0}}^2## and ##1 a.u.=5.14*10^{11} V/m## to obtain...

Homework Statement There's an elastic collision between a photon of energy E and an atom in an excited state. After the collision, the energy of the photon is still E but its direction changed of angle of 180° and the atom is now going back with velocity Bc. If the atom is in his ground state...

What would be the difficulty of building each? I have read of Michio Kaku building an atom smasher (albeit it ruined the power flow to his house,) I have found a 200,000 volt generator so I presume that a particle accelerator would be possible, and my friend is currently working on a nuclear...

I know that when you draw the lewis structure for chlorate, the chlorine goes in the center with the oxygen bonded to it. What I don't understand is that the teacher told me that the central atom is the element with the fewest valence electrons. So wouldn't that make oxygen the central atom...

Imagine that an excited hydrogen atom in the symmetric 2s state emits a photon. We use a birefringent crystal to split the photon into vertical and horizontal components. Is the phase relation between these components random or is it the same for every photon emitted by a similarly excited...

When solving the three dimensional Schrödinger equation, we obtain a probability distribution on θ. But it seems like the procudure produces a particular direction the z-axis. While the Coulomb field is spherical symmetric, it shouldn't exist such a preferred direction. I'm puzzled.

Hi, If we have a system on N atoms confined to dimensions much smaller than the wavelength corresponding to the transition, we see superradiant decay. Now, in these cases, we always assume that the excitation is symmetrically or antisymmetrically distributed. For instance, if we have one...

Homework Statement "Calculate how much energy that is required for a oxygen atom 168O to split it up into 4 α-particles" The Attempt at a Solution 1: (8 * 1,00727646688)u + (8* 1,00866491578)u = 16,12753105 u The first one is the Oxygen's 8 protons and the second one is its 8 neutrons...

Homework Statement An alpha particle traveling with a kinetic energy of 5.5 MeV and a rest-mass of 3727.8 MeV/c^2 strikes a gold atom with a rest-mass of 183,476 MeV/c^2. -The gold atom is initially at rest -The alpha particle deflects perpendicular to the horizontal in the after state...

So firstly, the book supplies the answer of \Delta\lambda = \frac{h}{2mc} I use energy and momentum conservation. I say the total energy is that of the incoming photon, which is then changed to energy of the photon released, and kinetic energy of the atom, from the recoil. I say the same...

What potential would one use when evaluating the Dirac equation of the hydrogen atom? Would it simply be in the form used when examining the hydrogen atom-Schrodinger equation or does it need modification?

I'm studying the Bohr's hydrogen atom and my teacher gave us a challenge question. When I was working in the problem I've got a couple of other questions that I don't know the answer. The initial problem was the following: Today we know the electrons are not the only particles moving inside...

I have a fairly straightforward question: how does one formulate the problem of hydrogen atom with quantum field theoretical treatment? I understand that one can just take Uehling potential and find approximately the bound states' energies and wave functions, but it would not make electron...

Hello, all, I have a question about the wave functions of H atom: for p orbital, wave functions from the Schrodinger equation are p+1, p0, and p-1. In chemistry, people use the linear combination of p+1 and p-1 to generate px and py orbitals. The question is: p+1 and p-1 orbitals are...