Hydrogen Definition and 1000 Threads

  1. K

    The dirac equation of the hydrogen atom

    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?
  2. edpell

    Hydrogen molecule in a small box, thought experiment

    What would happen if we placed a hydrogen molecule in a box with sides less than the Bohr diameter. That is, a box so small the electrons could not orbit around the protons at a distance of a Bohr radius. What state would the two electrons and two protons take?
  3. jaumzaum

    A lot of considerations about the Bohr's Hydrogen Atom

    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...
  4. P

    The Bohr-Rutherford Model of Hydrogen

    Homework Statement In the Bohr-Rutherford model of hydrogen,the electron moves in a circular orbit about the proton. Homework Equations I = e/t = e*v/2*pi*r I = current , e = charge , v = velocity , r = radius The Attempt at a Solution 1)Calculated the electric current...
  5. D

    What is the Darwin Term's Role in Hydrogen's Fine Structure?

    I'm trying to do a HW involving the Darwin Term in the fine structure of hydrogen. I'm given that the perturbation from the Darwin term is equal to (times a constant factor which I'll ignore), V_D = [p_i,[p_i, \frac{e^2}{r}]] = e^2\vec{p}^2\frac{1}{r} -2e^2\vec{p}\frac{1}{r}\vec{p} +...
  6. B

    Iodide Oxidation by Hydrogen Peroxide

    In my chemistry lab we prepared the following solutions: Buffered Iodide Solution 25 mL acetic acid/sodium acetate buffer 6mL of 0.5 % starch solution 6 mL of 1.0M KI fill to the 250 mL mark with distilled water 0.025M Thiosulfate Solution 5 ml of 1 M Na2S2O3 fill to the 200 ml mark...
  7. A

    Spin orbit coupling and hydrogen problem

    I don't know if you are familiar with it, but in pertubationt theory for hydrogen it is handy to look for eigenstates of J = L + S since this commutes with the hamiltonian (L and S are not separately conserved). My book then says that the good quantum numbers are: n,l, j, mj I must admit I'm...
  8. L

    QED Hydrogen Atom: Formulating and Solving Problem

    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...
  9. F

    Angular momentum of excited electron in hydrogen

    I am sure there must be a better way to do this, but I just used the method I thought would work. Essentially, I just want to find n and put that in p=nh2π, but my method to find n will give me a complex answer, which is clearly not what I am looking for. If someone could either tell me what...
  10. Q_Goest

    Can Perlite Be Used as Vacuum Insulation for Cryogenic Hydrogen Tanks?

    Cryogenic liquid hydrogen tanks are common in industry. These tanks have an inner vessel and an outer vessel. Between the two, the space is sometimes filled with perlite and a vacuum pulled to reduce heat transfer to a minimum to prevent boiling of the liquid hydrogen. This is the same...
  11. K

    Energy flux in optics in hydrogen gas

    Homework Statement There is a half space z>0 full with hydrogen gas with density n atoms / metres cube. An incident wave plane with pulsation ω coming from z = -∞ arrives at the surface of incidence. This wave transports a flux of energy ∅0 at z=0. We consider a elementary cylinder whose axe...
  12. G

    How many cubic feet of gaseous hydrogen are in one gallon?

    Hello. I'm just wondering how many cubic feet of gaseous hydrogen are in one gallon of liquid hydrogen. I know I'm not being too specific and that many variables are involved (temperature, atmospheric pressure... etc), but approximately how many are in a gallon? And yes, I have checked...
  13. B

    Reaction between Copper, Hydrogen Peroxide, and Vinegar

    Hey there PF, I'm trying to determine the reaction equation for a little home experiment I've been conducting. The setup is very minimal: copper metal in a solution of 3% H2O2 and 5% CH3COOH. In reality, I'm probably missing something fairly straightforward. The reaction occurs very...
  14. C

    P-subshell orbital of Hydrogen

    I'm trying to understand electron orbitals. I'm a beginner. I'm looking at the shapes of p orbitals in a chemistry book, and it's talking about Hydrogen. I'm surprised to see that the orbitals are not spherically symmetric. How can that be when the nucleus is spherically symmetric? Can a...
  15. S

    Estimating the vibrational frequency of Hydrogen molecule

    Homework Statement A diatomic molecule, when excited, can vibrate in such a way that the relative distance between the two atoms, r(t), executes periodic oscillations. If the potential energy of the molecule as a function of r is given by V (r), the time dependence of r(t) is identical to...
  16. O

    Finding the ratios of diatomic, monatomic and ionized hydrogen

    Hi, Would a clump of gas in space have some diatomic molecules in it as well? If it does, how do we find the ratio? I know that hydrogen gas at room temperature on Earth is diatomic. So I guess the state of the gas molecules change like this. Diatomic molecules -> Monatomic ground state ->...
  17. B

    Is Rest Mass of Hydrogen Affected by Virtual Particles?

    Hello all . Rest mass of Hydrogen is more than rest mass of one proton and one electron ? I mean virtual photon between electron and proton give extra mass to Hydrogen ? Like gluon between quarks ? and another example : mass of solar system is more than mass of One to One planets and sun...
  18. J

    Hydrogen bond vs dipole-dipole?

    I saw a video on youtube saying water molecules were held together by hydrogen bonding, not dipole dipole. Why is that?
  19. J

    Is Hydrogen a Metallic Element?

    I asked my chemistry professor this question, and he gave me a brief answer of "yes and no", and I never followed up to explain that. Hydrogen is in the same column as the alkali metals, and it does donate electrons. However, it is gaseous and found diatomically (making it similar to some...
  20. J

    Hydrogen Cations: The Wandering Protons of Chemistry

    Let's say there a particular hydrogen atom would be a rare-occuring hydrogen atom without a nuetron. And let's say it's a cation that donated it's electron. Would it essentially be just a wandering proton?
  21. L

    Molecular hydrogen excitation levels

    Hi, I am looking for electronic excitation levels of molecular hydrogen like attached table. but there are only a few electronic states, i need near-threshold energy levels. where can i find all levels? thanks for attention http://imgim.com/5648inciz1637947.jpg
  22. P

    Q about current article: On-demand Hydrogen Generation : ACS Nano Letters

    Here is the abstract: http://pubs.acs.org/doi/abs/10.1021/nl304680w I would need to pay the $35 so I have not read the full text. Question: it says "...without Light, Heat, or Electricity." Where is the energy required to split the water molecules coming from? Jeff
  23. A

    Question-Rant on Hydrogen to Helium Fusion, and Proton to Neutron Conversion

    Part 1----------------------------------------- Ok, the site I have just read through is http://burro.astr.cwru.edu/stu/stars_lifedeath.html one. I have a few questions about it. Firstly, about the fusion of helium into hydrogen... http://burro.astr.cwru.edu/stu/media/fusion.jpg It...
  24. F

    Splitting Hydrogen into Atomic Molecules Using an Electric Arc and UV Lamp

    One molecule of diatomic hydrogen H2, passing through an electric arc between tungsten electrodes, splits into hydrogen atoms by absorbing a considerable amount of heat: H2 + 103Kcal = H + H = H2 + 103Kcal Atomic hydrogen, recombining into molecules, being unstable, after 0.5 seconds, gives a...
  25. R

    Hydrogen Fluoride gas mixture quantities

    Hi, I am not a chemist but maybe there is somebody who can help me. I need a put together an emergency plan as part of a college law assignment on European Seveso directives. My case study has 17t of Hydrogen and 8t of Fluorine. Both of which combine satisfy the requirement for a lower...
  26. L

    Help solving the TISE for the hydrogen atom

    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...
  27. Islam Hassan

    Hydrogen Fusion Cycle in Stars: Storage/Transport/Consumption?

    I have always been wondering how in an active star the H/He fusion cycle is "managed" for lack of a better word, a little like a logistical analogy really. Specifically: i) Where in the star is the yet-to-be-fused H 'stored'? ii) Where in the star is the He result of fusion 'stored'...
  28. C

    Hamiltonian for hydrogen atom?

    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.
  29. 4

    Natural Gas to generate hydrogen, fuel cell?

    Hi all, one last question for today - Given steam reforming of natural gas to generate hydrogen, what is the major difficulty with it with respect to most fuel cells? Thank you,
  30. D

    Velocity of Electron ionized from Hydrogen

    Homework Statement Ultraviolet light with a wavelength of 45.0nm shines on a gas of hydrogen atoms in their ground states. Some of the atoms are ionized by the light. What is the kinetic energy of the electrons that are freed in this process? I found the kinetic energy right but for some reason...
  31. J

    Transition Probability of Hydrogen atom in an electric field

    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...
  32. E

    Orbital angular momentum possible values of an electron in a hydrogen atom

    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...
  33. L

    Probability density of an electron of hydrogen

    Hi everyone Homework Statement What's the probability density of an electron at a distance r (from hydrogen) which is in the stae n=2, l=1. Homework Equations - The Attempt at a Solution I think I have to to solve \int |\Psi_{nml}|^2 dV The solution of the Schrödinger...
  34. D

    What is the Hydrogen Emission Spectrum for Transitions to the n = 1 Level?

    Homework Statement What wavelengths emitted from a hydrogen gas discharge tube are associated with transitions from higher levels down to the n = 1 level? [a] infrared [b] visible [c] mixture of infrared and visible [d] ultraviolet Homework Equations Equations: 1/λ =...
  35. S

    How much water needed to power the world through oxidization of hydrogen

    Homework Statement The annual world use of liquid hydrocarbon fuels for transportation purposes currently generates about 10^17 kJ. If we could instead run our transportation system by oxidizing hydrogen gas to gaseous water, we would likely have to obtain the hydrogen by electrolyzing water...
  36. D

    Energy of a Hydrogen Flouride molecule in normal mode vibration

    Homework Statement Hi everyone! first post here :) Basically, the question is as follows: Consider a hydrogen fluoride molecule (atomic mass of H is 1g/mole and of F is 19 g/mole). 1. Write the energy of the system in terms of the displacements of both atoms. There are other questions...
  37. P

    Understanding Hydrogen Bonding in Ethanol Molecules

    Hey, How do you know how many hydrogen bonds ethanol molecules will form with each other? I know there are 3 sites where H bonds could form (2 lone pairs on oxygen and the hydrogen) but with something like hydrogen fluoride, each molecule only forms 1 H bond on average so shouldn't something...
  38. H

    Why is hydrogen stable but lepton pairs aren't?

    I probably knew the textbook answer to this at one time, but I don't recall. Feynman states in the beginning of Vol II of the FLP that electrons don't collide into the nucleus due to the uncertainty principle. But an electron positron pair will mutually annihilate. I suspect the answer has...
  39. N

    Photon emitted by a hydrogen atom in Lyman series and Balmer series at once ?

    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...
  40. S

    Hydrogen and oxygen used as fuel in internal combution engine

    why cannot hydrogen and oxygen not used in internal combution engine as fuel? it would be pollution free.
  41. N

    Energy of H Atom in 1st Excited State - 23.8 eV

    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...
  42. V

    How is hydrogen more stable in diatomic form?

    Hello Physicsforums, I'm curious to know what stability hydrogen receives through adding one more electron to its 1s sublevel level. The whole sublevel is at the same energy state, so why must it fill that one more space to attain stability? What does a full 1s orbital do to make it...
  43. C

    Is the Hydrogen Energy Level Formula Truly Degenerate in j?

    Griffiths writes that the formula for the hydrogen energy levels taking fine structure into account "breaks the degeneracy in l" but "still preserves degeneracy in j." I'm confused by this, because the formula he gives (Eq. 6.67 in the textbook) depends on j. How can the system be degenerate...
  44. H

    If water is covalent, why is hydrogen H+ ?

    Water is covalent compound. But formation of water is written as: H+ + OH- = H2O I cannot understand why hydrogen is electrically positive in the above equation. Hydrogen wants one more electron to complete its first and last shell (total two valence electrons). Hence, hydrogen should...
  45. M

    Energy of an electron in hydrogen

    What is the energy of an electron in the 2s orbital of a hydrogen atom? I thought En = -RZ^2 / n^2 Why am i not getting the right answer with Z = 1 n = 2 and R just the value of the constant
  46. D

    The radius of the Stationary State of a hydrogen atom

    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...
  47. M

    Find the Initial and Final states of an excited Hydrogen Atom

    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...
  48. D

    Neurtal hydrogen atom net electric charge and electric field at Bohr radius.

    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...
  49. H

    What is the difference between Hydrogen and Protium?

    I hope this is posted in the correct forum; From what I remember in school, Hydrogen (atomic weight 1) consists of 1 proton and 1 electron with 0 neutrons. Protium is an isotope of Hydrogen, which I assume makes it slightly different than H as is listed on a periodic chart, yet from what I...
  50. R

    Spectrum of Sodium vs. Hydrogen

    My question is: Why the energy levels for sodium are different from those for hydrogen even though sodium is described as a "hydrogen-like atom"? Here I have posted the energy diagrams for sodium, and hydrogen. So, I have noted that sodium has 11 protons, whereas the hydrogen has only 1...
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