Atom Definition and 999 Threads

Hi all,If there is activation energy for chemisorption, then an atom with insufficient energy to overcome that barrier will remain physisorbed to the surface via van der Waals forces. I would like to further understand this activation energy in terms of, for example, the overlap of electron...

How Number of elementary particles in an atom are counted?

Try as I may, I can't figure out how to even phrase the following in a way to google it, so I apologize in advance if it is a trivial question, I am no physicist. What I am trying to discern is if there are very very small shifts in the perceived charge of an atom over very very small amounts...

I am interested in what the recoil velocity of an initially stationary hydrogen atom in free space would be when it emits a Lyman alpha photon. I tried to do the calc and got about 3 metres per second which seems rather high.

In the stern-gerlach experiment, silver atoms with a +1/2 would be deflected up, and atoms with a -1/2 spin would be deflected down. With that in mind, would electrons' orbitals within an atom be affected by its spin?

Simpel question: does an atom consists of matter and charge? Yes/no?? If no Then what?

Is there a standard velocity for a proton when and if it is released from an atom?

I've been trying to find a source for this somewhere, but I always end up with different sources explaining what holds protons and neutrons together in the nucleus of an atom. I know that the gluons hold them together, but I'm not sure exactly how they do this, and what type of transfers occur...

In an atom of something like oxygen with a completed 2p orbital, do the paired electrons within the orbital behave differently than the same 2p orbital that is uncompleted? Bear with me and try to understand this question as I am a little fuzzy on the subject and I don't know how else to ask...

Homework Statement [/B] In a certain organic molecule, the nuclei of 2 carbon atoms are separated by a distance of .20nm, What is the magnitude of the electric repulsion between them? Now, I know the distance between them, but it has to be converted into meters: .20nm = .20 X 10 ^-9m And...

In my book it is says, DeBroglie wavelength of a particle at temp T is, λ = h/√(2mKT) and DeBroglie wavelength of He atom is, λ = h/√(3mKT) Well, λ = h/ mv and mv2/2 = (3/2) KT and so , λ = h/√(3mKT) How to prove the first one..?? and why they are different...??

The atom that is used as the standard for the atomic mass scale is the Carbon atom with an atomic number of 6 and a mass number of 12 and this carbon atom is equal to 12 unified atomic mass units. Could another atom be used as the standard, and if so, how would this be accomplished??

Protons and Neutrons vibrate in place, but do they change positions within the nucleus? Let's say that there's a helium atom which has two protons and two neutrons. If the particles were set up on the corners of a square for easy representation with a neutron on the top left and top right, and a...

What's the mass difference between a hydrogen atom and it's constituent particles when they are free, I'm talking about the proton and the electron, not the quarks that make up the proton.

What are the different ways that have been used to keep a single atom in a specific location?

Not quite sure how to ask this, but here goes: I think I understand how a photon impacting an atom can increase the energy level of an electron in the atom. When I read about "light pressure", I thought, is there a way for, say, a stream of photons to accelerate an atom by continually impacting...

Can someone give me a simple explanation of how to measure the Rabi probability oscillations in a two state atom?

Homework Statement A singly ionized atom exhibits hyperfine structure in a ##^3P_1 \rightarrow ^3S_1## transition. Assuming ##I## is greater than ##J## and given that the ##^3S_1## levels are split by ##66~GHz## and ##54~GHz##, find the nuclear spin ##I##. Homework Equations E_{HFS} =...

Hey I was reading through a text and came across: I can understand the second statement from the Pauli matrices... However I think that I don't understand the 1st statement as it is... why would the diagonal elements of an odd-operator be zero if parity is definite?

Does the energy of the electron in a random hydrogen atom is in superposition of all eigenvalues(some value upon measurement) or you will find it most likely in the ground state. Additional clarification: From my reading the textbooks said the electron energy is in superposition, yet the...

Homework Statement An atomic clock moves at 1,000 km/h for 1.00 h as measured by an identical clock on the Earth. At the end of the 1.00 h interval, how many nanseconds slow will the moving clock be compared with the Earth clock? Homework Equations (1/ sqr rt 1 - v^2/c^2) The Attempt at a...

After calculating the force upon an electron and a force upon a proton in the atom of hydrogen, my result was a force of ≈8.2x10-8 Newtons acting upon the electron and proton each. If found this by using the formula Fe = (ke q1q2)/r2 Taking this number, I then applied it in the formula F = ma...

Studying the production of the bound state of ##μ^+μ^- ## in the scattering experiments of ##e^+e^-## at electron positron colliders ##e^+e^-\toμ^+μ^- ## via ##e^+e^-\to 2γ\toμ^+μ^- ##. This bound state further can decay into ##e^+e^-## or ##2γ##. I am confused about the vertex ## 2γ\toμ^+μ^-...

Good morning everybody, here's a problem about excitations energy of the core level of a Sn atom. It says to construct the scheme of the core levels of Sn indicating the excitations energies. Now the K edge (the problem doesn't say we are necessarily talking about X-rays, but I think we are...

when I say one atom, I mean literally just one atom isolated and if so how would you measure it?

Just look at the first point.It says the given compound has four types of hydrogen atom.How?I can only see three types of hydrogen atom primary,secondary and tertiary which is the fourth type?Please give me a hint.

My notes states that fluorine is too highly electronegative and hence clings on too tightly to its lone pair of electrons and so it cannot accept hydrogen bonds as well. However, it also stated that a hydrogen bond will be stronger if the electron density on the electron rich atom the stronger...

What happens if a hydrogen molecule is stripped of an electron? Will it become 2H+ or will it become H and H+?

Why ionization energy is defined as the energy required to remove the outermost, or highest energy, electron from a neutral atom in the gas phase. Why can't we remove electrons from a solid,can we? If not ,what's the reason?I think we can not remove electrons from a solid because in gas phase...

Please explain me 1. How Absorption and Re-emission happens in an atom 2. A common explanation that has been provided is that a photon moving through the material still moves at the speed of c, but when it encounters the atom of the material, it is absorbed by the atom via an atomic transition...

A neutral atom of radium isotope may be represented by: 228 Ra (88 proton number, 228 nucleon number). 88...

Homework Statement For a hydrogen-like “atom” (e.g., He+ ion), with nuclear charge Ze, it is claimed that the the ground-state wavefunction is spherically symmetric and is given by ψ(r)=Aexp(−αr) , where A and α are constant. (a) Determine the normalization constant A in terms of α. (b)...

what is the best referece book to study atomic structure and electronic structure of atoms ?

Homework Statement After turnig of magnetic-optic pit, cold cloud of atom 87 Rb is expanding. Size of cloud after time t, is given with relation: where, k_B is Boltzman constant, m mass of 87 Rb. Draw a plot, then use least squares method to find temperature T, and initial size of cloud...

Hi everyone, I'm trying to simulated the XRD pattern of Bi2Sr2Ca2Cu3O10, but I'm having a problem of finding the basis of atom(and their respective position). Also its JCPDS is quite hard to find, so if anyone working with this, may you provide a link or articles about my problem. Thanks...

When using the variational method for the Helium atom, we determine that the lowest possible energy occurs when 1<z<2 where z is the atomic number. My professor elaborated that the number is within this range because there is a probability that the electron may be so close to one of the protons...

When you hit a hydrogen atom with a photon, would it always register a hit 100% of the time? so do you have to compute for probability if it would hit it? I'd like to know if it is the photon wave function that interacts with the electron wave function so there should always be a hit all the...

How would one calculate the de Broglie wavelength of the proton in the hydrogen atom as the electron and proton pirouette around their common center of mass, for the lowest orbital? I believe the center-of-mass of the system would actually be inside the proton due to the great differential in...

For diamagnetic materials, when an external magnetic field is applied, the electrons having orbital magnetic moment in opposite directions spped up. how does this happen? The direction of magnetic momwnt is given by right hand thum rule. If there is an electron revolving in anticlockwise...

I've been following the EdX course on Quantum Computing by Prof. Vazirani and I don't understand how one physically can create a superimposed state of the ground and 1st excited state of an hydrogen atom. He mentions "the use of light," but doesn't explain the frequency of the light, nor the...

Why do electrons further away from the nucleus have more energy? When my book mentions energy in different orbitals, is it talking about potential energy? If it is, I'm confused because potential energy is inversely related to distance, so if distance increases, the potential energy decreases.

I was wondering, in the context of electron excitation and electron affinity, what it meant when we say that the electron absorbed energy or released energy. I think for electron excitation, the photon's energy, which is in the form of work= force time distance from the photon particle is...

I was wondering if alpha particles created by radioactive decay ever have enough energy to fuse with something else (e.g. hydrogen or another alpha particle).

Right, on the huge hypothetical atom I asked about before; what I'm really after is how the electric field from a point charge is quantized at a macroscopic distance of several centimeters? Let's say that you charge a metal electrode with C Coulombs of negative charge and then use that electric...

Homework Statement The energy of an electron in a hydrogen atom is: E = p^2/2m_e - \alpha e^2/r; where p is the momentum, m_e is the electron charge magnitude, and \alpha the coulomb constant. Use the uncertainty principle to estimate the minimum momentum in terms of m_e, a, e, \hbar...

Why there is no electron-positron production inside the, let say, Hydrogen atom?. I know that the electric field near nucleus get modified by some form factors making it not as big as the Coulomb field, but still i think is still very big.

Homework Statement What is the ratio of the average speed of an atom of neon to another atom of neon at twice the temperature? (A) 1:1 (B) 1:1.4 (C) 1:2 (D) 1:4 Homework Equations KE = 3/2RT The Attempt at a Solution I used the above equation and substituted 2 for T for twice the temperature...

I´m looking for a software that would allow me to test atom interaction acurretly in 3D, with public variables (i.e. customizable parameters) like the pressure and the temperature. I´m looking for something that takes into account S, P, D orbits with their real shape and the real numbers of...

Homework Statement In 1911, Ernest Rutherford discovered the nucleus of the atom by observing the scattering of helium nuclei from gold nuclei. If a helium nucleus with a mass of 6.68 10^-27 kg, a charge of +2e, and an initial velocity of 1.30 10^7 m/s is projected head-on toward a gold...

I found this in a Phd thesis consider a two level atom interacting with the electromagnetic field. The atom is described by ##H_{at} = \hbar ω_0 J_z## a monomode electric field is described by ##H_{em} = \hbar \omega (a^\dagger a + 1/2)## We have ##E = E_0(a^\dagger + a)## and the dipolar...