Atom Definition and 999 Threads

Can someone post the most precise atom or molecule real pictures at present?

When we shine light on an atom, it can absorbs this radiation, stimulating its electrons to jump to a more energetic energy level. This lasts too little time, and when the electrons come back to their original (fundamental) energy level, they emit the same energy they had absorbed before. This...

When looking at a Chemical, what does this mean... "99.9 atom % D" Hey, can someone explain to me what this means. Lets use D2o for example (Deuterium oxide) 1 store says "99.999 atom % D" And the other store simply says "DEUTERIUM OXIDE 100% D,99.96% " Can someone please shed some...

Can someone please help me on this physics question The mass of a copper atom is 2.50 10-25 kg, and the density of copper is 8 920 kg/m3 . (a) Determine the number of atoms in 1 cm3 of copper. (b) Visualize the one cubic centimeter as formed by stacking up identical cubes, with one...

Simple and stupid question! A Be atom is traveling with 60 kev kinetic energy and splits into two helium atoms, and the process itself releases 92.2 kev. One helium atom moves at a 30 degree angle with respect to x. find the direction of motion of the second helium atom and find the velocity...

Can electromagnetically induced transparency, be effected on a single atom within a molecule? Thanks, Jake

How did scientists/chemists experimentally determine how many electrons an atom has? Hydrogen, carbon, oxygen, etc... I'm wandering what physical experiment would tell you how many electrons an atom has?

Homework Statement Hi guys the question is "Write down the time independent Schrödinger equation for the hydrogen atom, and show that the wave function Ψ(r,θ ,φ ) = Ae(−r / aB) is a solution. (A is a normalization constant and aB is the Bohr radius.) What is the energy of the state with this...

When I write down the Hamiltonian for the hydrogen atom why do we not include a radiation term or a radiation reaction term? If I had an electron moving in a B field it seems like I would need to have these terms included.

A hydrogen atom is in its ground state and is subject to an external electric field of E = ε(\hat{x}+\hat{y}+2\hat{z})e-t/\tau I'm confused as to how to compute the matrix elements of the perturbed hamiltonian since this is not in the z direction. Would I have to do something like this...

Homework Statement A Na atom is in an excited state for a mean time of 1.6 \times 10^{-8}s. Then it jumps to the ground state emitting a photon with 2.105 eV of energy. Find the energy uncertainty of that excited state. Homework Equations The Attempt at a Solution I don't even...

Homework Statement What are the orbital angular momentum possible values for an electron in a hydrogen atom with a principal quantum number n = 3? Homework Equations L = \sqrt{l(l+1)}\hbar The Attempt at a Solution Possible values for l are 0, 1, 2. So, substituting these in...

Homework Statement In a Stern-Gerlach device, an atom beam with angular impulse J, travels through a magnetic field applied normally to the trajectory. The beam is separated in 2j+1 beams in general. Find the relative intensities for these beams if J=1 and if the beam is polarized with jθ=1 in...

Homework Statement Whenever a photon is emitted by hydrogen atom in the Balmer series, it is followed by a photon in Lyman series . What wavelength does this latter photon correspond to ? Homework Equations Balmer series corresponds to the wavelengths in the visible spectrum and Lyman...

Homework Statement What is the energy of H atom in the first excited state if the potential energy in the ground state is taken to be 0 ? Homework Equations Usually the energy of H atom in the ground state is -13.6eV and in the 1st excited state is -10.2eV E(n) = πme2/8ε2h2 Bohr's...

Given a simple atom like the Bohr atom (and possibly generalized to any other atom), I know that an electron can transition from one energy level to another, either by absorbing or releasing a photon of a precise hf. How much time does an electron take to make a transition from one energy level...

Homework Statement There are a few problems I have with my HW that involve the characteristic size of an atom in a certain state. For example, the hydrogen atom in the ground state. Homework Equations - The Attempt at a Solution I don't know where to begin to find the characteristic...

Hi I am in a material science class and one of my homework questions states: "Calculate the radius of an iridium atom,given that Ir has an FCC crystal structure, a density of 22.4g/cm^3,and an atomic weight of 192.2g/mol." I think I have to use the Pythagorean theorem somewhere but my...

Homework Statement A Hydrogen atom is in a state with n=2? Homework Equations r=an^2 a=.0529 nm The Attempt at a Solution I am confused by my book it says that the radius of a stationary state is r=.0529*2^2=.2116 but I disagree isn't the stationary state n=1 which would mean the...

Homework Statement A hydrogen atom in an excited state absorbs a photon of wavelength 434 nm. What were the initial and final states of the hydrogen atom? Homework Equations 1/λ=1/91.127 * (1/nf2-1/ni2) The Attempt at a Solution Tried to use the equation, but keeping the initial...

Homework Statement An atom of mass M decays from an excited state to the ground state with a change in mass of ΔM<<M. In the decay process, the atom releases a photon. Use the laws of energy and momentum to determine the energy of the photon, assuming the atom decays from rest. Homework...

What is the origin of the internal magnetic field in an atom (which gives rise to spin-orbit interaction in an electron). The energy associated with this field is calculated using the reference frame of the electron and then returning back to the nucleus reference frame (thomas precision). But...

Homework Statement https://www.physicsforums.com/attachments/51461 https://www.physicsforums.com/attachments/51462 Hi! I got stuck in studying the book "introduction to electrodynamics" written by griffith I attached the related pictures above. The page is p.161-p.162. It's concerned...

Homework Statement The HCl (hydrochloric acid) molecule has a dipole moment of about 3.4x10-30 C.m. The two atoms are separated by about 1.10-10 m. What is the net charge on each atom? What is maximal torque that this dipole will experience in a 5.104 N/C electric field? How much energy one...

I know this question is probably fairly basic but I had a hard time finding an answer on google. Does a single atom vibrate/jiggle/oscillate if it has a temperature (ie is not at absolute zero)? Is this vibration random in direction? If it is random, wouldn't this violate the law of...

I am studying for my exam and I have run into this problem. The problem is given here http://faculty.mint.ua.edu/~pleclair/PH253/Homework/Spring_2010/HW6-7_atoms_12Mar10/HW6-7_atoms_12Mar10_SOLN.pdf"],[/PLAIN] it is #9. I don't understand why -e ≠ ∫ρdV from 0 to the bohr radius, a0. If all...

I find that I cannot find some simple and basic data - when I search, I find recent articles working on advanced extra experiments, but basic facts are taken for granted there and not repeated. What happens to a muon in an atom? Obviously, a free muon decays μ->e+ν~e+νμ with lifetime...

A sole hydrogen atom in a vacuum (negligible gravity). The hydrogen atom has the lowest possible kinetic energy allowed by QM. Given that casimir effects apply... Will the hydrogen atom remain at it's initial lowest kinetic energy state indefinitely or is it possible for it's energy state to...

Hello all, Many Physics texts simply say that atoms "vibrate" when heat energy is transfer to a metal bar when it is heated. Or that molecules vibrate as the result of heat transfer. I'm trying to understand what makes an atom or molecule "move" or oscillate when energy is given to it. If I...

I understand that He- is larger than He, but I don't know which is bigger between He- and Ne.. please help??

Homework Statement If there are 13 electrons in M shell and one electron in N shell, the the number of unpaired electrons in such atom will be Homework Equations M- shell N- shell The Attempt at a Solution The configuration should be 3s2 3p6 3d5 4s1 hence the answer should be 6

I am given a critical bare slab reactor 150cm thick (a0=150cm) consisting of a homogenous mixture of U235 and graphite. I am stuck on the part which asks me to calculate the critical atom dennsity. I have solved for the mass of the fuel in terms of the mass of the moderator. I would solve...

In its ground state, an atom has no net electric dipole momentum ,but it can have a nonzero angular momentum. Is this a spontaneous symmetry breaking? why the ground state is not of zero angular momentum?

Hi,Everyone! I have a question! We often say hydrogen atom spectrum. But in nature ,it exists in the form of molecular hydrogen. today, I read something about hydrogen atom spectrum experiment. In the experiment ,we use hydrogen lamp. The Hydrogen lamp is a long glass tube filled with Hydrogen...

Here's a pic from Sean Carroll's lectures on Dark Matter and Dark Energy available through the Teaching Company: I just want to double check, there are two types of atoms, if I understand the delayed choice experiment correctly, just the knowledge that you can detect the atom transforms...

Does this decay leave the He3 atom with only one electron? The only decay productsas far as I can tell are the electron and antineutrino, so it seems like the atom would only retain the original H3 electron. Now if that's the case, why is the beta decay electron emitted rather than fitting...

Hi, a question I have been asking myself is what where to happen if we where to look deeper into the atom? Is there a point in where there is really nothing? As far as I know it only goes down to quarks. Is the quark the end of it or is there more?

is it pauli or schrodinger? is there any original reference?

1. Homework Statement and attempt at a solution Considering that the ground state of the beryllium atom is 2s^2 and the first excited state is 2s2p, I was wondering in how many lines would the emission/absorption spectrum be modified in a weak magnetic field. I know that if there's no...

Hello guys - my first post! Why do we have neutrons and protons in the center and electrons around them? Was the atom like this since the beginning of the universe(or rather did atom exist in the beginning) or did it get structured in this way after sometime? Did the neutrons, electrons and...

i've read a theory about dark stars resently and I've got some questions that's been gnawing at my mind, hope i can get some answers here. 1: what is the size of an atom? as in if the nucleus was the sun, where would the electrons be? i know diffrent substances has diffrent atom sizes but for...

Homework Statement He+ ion consists of a nucleus which is an alpha particle plus one orbiting electron.Hence it has a net positive charge. a)Derive an expression for the electron state energies b)what is the wavelength associated with a transition between the lowest two energy states...

All I need to evaluate the normalization coefficient. I need a step by step guide. It will be a great help if someone please tell me where can i get the solution (with intermediate steps). I think the solution can be done using the orthogonal properties of associated Laguerre polynomial. I need...

"Prove that the Bohr hydrogen atom approaches classical conditions when [. . .]" Homework Statement The problem and its solution are attached as ProblemSolution.jpg. Homework Equations E_k = chR/(n_k)^2 E_l = chR/(n_l)^2 ΔE = hc/λ hc/λ = chR[1/(n_k)^2 – 1/(n_l)^2] 1/ λ = R[1/(n_k)^2 –...

What exactly is it that makes the energy/mass of a hydrogen atom be lower than that of the electron and proton separately? I am aware that this process is what causes stars to emit light, during nuclear fusion deuterium has a smaller mass than a proton and a neutron so its extra mass/energy is...

If photons have a quanta of energy tied to its frequency, and the energy state of an atom can only be at specific levels, does this mean that atoms will only interact with certain wavelengths of light? As an example, hydrogen emits a photon with a wavelength of 486 nm in one of its state...

We know this tiny splitting in degenerate levels in Hydrogen spectrum due to magnetic interactions between spins of electron and proton. but is that true the proton spin is independent of energy in this (hyperfine) splitting? I want to understand the physics of this splitting and how the spin...

why is hydrogen the only element in the periodic table that lacks a neutron?

When a photon has a wavelength close to the energy needed for an electron jump in an atom, the atom will absorb the photon. How close must the wavelength be to the energy required for the atom to still absorb it?

At an altitude of about 100km above the Earth's surface, the density and temperature of the atmosphere are about 10^-14 kg/m^3 and 2000K, respectively. At this altitude, the major constituent of the atmosphere is atomic oxygen. Use this information to estimate the pressure of the atmosphere at...