Atomic Definition and 853 Threads

  1. T

    Question about the atomic structure of insulators

    I'm an apprentice electrician taking night courses. My question isn't a specific mathematical problem. It's a query about a concept. Please let me know if there's a better way/place I can ask it. My text say that atoms can have a max of 32 electrons per shell, with 1-3 being ideal for...
  2. B

    Sub atomic collision and modulation

    when two sub atomic particles collide, being waves as well as particles. at point of collision do they act like radio waves and modulate each other. Are the resultant particle/waves produced by collision equivalent to upper and lower sidebands (as in AM modulation) or bessel functions (as in FM...
  3. A

    How do compound objects maintain rigidity despite atomic vibrations?

    Hello, as we all know, in compound solids atoms are always vibrating with some degree, depending on the temperature or the average kinetic energy they posses. My question is how do compound objects maintain their rigidity in those conditions, or to say it better how do atoms stay in fixed...
  4. K

    Atomic Energy States in a Crystal: Einstein's Relation

    Does atoms in a crystal have energy states like electronic states? it is according to Einstein relation for harmonic oscillator.E=nhw
  5. O

    How can the atomic radius of any atom be accurately calculated?

    hello, I was wondering how the atomic radii where calculated. I have used the formula r=\frac{a_{o}n}{z*/n*} where z* is effective nuclear charge and n* is the effective principal quantum number but it seems to give me a bit different radii compared to the ones on Wikipedia...
  6. P

    Atomic Probability Densities Always Even?

    I know that for hydrogenic wavefunctions, the parity of a given state is (-1)^l . But does this mean that the probability densities for any such wavefunction is ALWAYS even? I'm trying to understand the Stark effect, and specifically why there is no first-order correction for he ground state...
  7. J

    Atomic and Ionic Radii in Relation to Periodic Trends

    1. I am a metal. My atomic radius is smaller than the atomic radius of the element with one fewer protons, but my +1 ionic radius is larger than the +1 ionic radius of the element with one fewer protons. Of the two elements in my group that have biological importance, I am the one with higher...
  8. D

    Question regarding negative atomic numbers.

    Hello my name is Dax, I'm currently in the world building stage of a science fiction I am writing and I came here to bounce some questions off of you fine people. My question is regarding atomic numbers of elements on the periodic table and weather it could be possible that negative atomic...
  9. B

    Help understanding molecular vs atomic electron quantum states

    I am a retired electrical engineer, now able to get back to studying what I really enjoy - mathematics and physics. As a genuine old geezer, my modern physics knowledge, which was never very deep, is now way out of date. I purchased a copy of "Modern Physics", by Kenneth Krane, and have been...
  10. S

    Software for atomic orbitals oveplap in molecules

    I would be most grateful for some tips of interactive software, which shows the hybridized atomic orbitals overlapping in the molecule (I don't mean resulting molecular orbitals but atomic orbitals of which overlapping forms MO). And does this works also in Mathematica?
  11. adoion

    Exploring Niels Bohr's Atomic Model

    hi, ive got a really simple question. niels bohr proposed a model of the atom in witch the electron cannot fall into any energy state but must fall be in certain discreet values and this helps explain why the electron doesn't clumb with the nucleus almost instantly. not the atom needed to...
  12. M

    Atomic recoil and the polarization of photon emitted

    Hi, i have a question about the center of mass change during photon emission in terms of the polarization of the emitted photon. first, a few facts are as follows: i) selection rule: if delta m=0, that means p (atomic recoil) = p (photon) in magnitude. This is of pi transition and...
  13. ThomasMagnus

    Balmer Series and Atomic Absorbtion/Emission

    Homework Statement This isn't a homework question, but I will try and follow the template. I am confused about the relationship between the absorbtion and emission spectrums for hydrogen. I was taught that in the balmer series for hydrogen, when an electron moves from the n=1 level to...
  14. J

    Radius of effect of atomic interactions

    Suppose that I have an atom in one corner of a room, and I fire a photon toward the opposite corner (and assume that it is absorbed there into the wall). There is essentially zero probability that that photon will interact with the atom (either be captured, or stimulate emission, or whatever)...
  15. Einj

    Find atomic number from spectral lines

    Homework Statement An atom or ion with one electron has energy levels E_n=-A/n^2. Tw neighboring lines in its spectrum at room temperature have wavelengths \lambda_1=97.5 nm and \lambda_2=102.8 nm. (Note that hc=1.240\times 10^{-6} eV m). (a)What is the constant A? (b) Identify the atom...
  16. J

    Can Atomic Clocks Measure Time Accurately Underground?

    Have there been any experiments using atomic clocks underground as a comparison to those on the Earth's surface?
  17. S

    MATLAB Plotting atomic orbitals on matlab

    Hi guys I've been having some trouble plotting the p(x) and d(xy) atomic orbitals on Matlab. I have been given that p(x) = x*e^-(x^2 + y^2 + z^2)^0.5 and d(xy) = x*y*e^-(x^2 + y^2 x^2)^0.5 Now I want to plot these orbitals on MATLAB using mesh or the surf command and then plot the...
  18. R

    Geometry of the atomic structure

    Hey guys, I was looking at both the time-dependent and time-independent schrodinger equations, and I notice that we often choose to solve these in spherical coordinates. I understand that we do this because they are convenient for problems with azimuthal symmetry. However, how do we know that...
  19. P

    How does atomic force microscope create tunnelling?

    http://gizmodo.com/5793309/worlds-first-single+electron-transistor-works-like-a-teeny-tiny-etch+a+sketch About the page above, atomic force microscope makes tunelling. But I didn't understand how it made tunneling? Would you explain how tunelling appears in a atomic force microscobe, please?
  20. xortdsc

    Field lines of electrons in an atomic orbital

    Hello, I have a rather conceptual question I couldn't really find an answer to yet. The electric field lines of an isolated resting electron would simply point from everywhere in space towards the position the electron is located in, with a length inversely proportional to the squared distance...
  21. K

    How were atomic masses determined before mass spectroscopy existed?

    I remember a professor mentioning something about how scientists did this when we were discussing the history of the periodic table (they originally ordered it by atomic mass). I can't seem to find an answer online without digging through a lot of stuff...there was one article on this topic...
  22. A

    How are particles excited to achieve high energy levels?

    Hello. I read about fast neutron therapy for cancer and the therapy uses a beam of high energy neutrons. How do you excite a particle to make it have "higher" energy.
  23. B

    Understanding How Atomic Clocks Work: Uncovering the Science Behind Timekeeping

    I just got an Atomic Clock and googled how they work. It says it picks up the Atoms in the Air and sets the Clock from finding out the Energy they emit or something like this. Can you tell me what I am missing or how they work?
  24. J

    Stress and strain from atomic point of view

    Hi all, This is a question regarding stress and strain. Can someone please explain the concepts of stress and strain in atomic level? My understanding is as follows.Let us consider a metal bar or rod that is subjected to tension.The load applied to the bar will be try to elongate the...
  25. A

    Is there such a thing as forbidden bound-free atomic transitions?

    So I've been studying forbidden transitions and metastable states in atoms, etc., and I was just wondering if there is such a thing as forbidden bound-free transitions? I've only encountered bound-bound. For example, if you have a neutral Helium atom with two electrons, I understand how...
  26. J

    Stress and strain atomic level

    Hi all, This is a question regarding stress and strain. Can someone please explain the concepts of stress and strain in atomic level? My understanding is as follows.Let us consider a metal bar or rod that is subjected to tension.The load applied to the bar will be try to elongate the...
  27. M

    Does Helium or Hydrogen have the greater atomic radius?

    I've been looking online at multiple resources and seem to be getting conflicting answers. http://www.sciencegeek.net/tables/AtomicRadius.pdf - Where He is slightly smaller than H http://intro.chem.okstate.edu/1314F00/Lecture/Chapter7/ATRADIID.DIR_PICT0003.gif - Where H is smaller than He...
  28. W

    Why does the atomic radii get smaller from the left to right?

    Why does the atomic radii get smaller from the left to right of a period but get bigger from top to bottom of a group? Wikipedia says in an article about electron shielding "Next we take Beryllium, Be as an example. It has 2 electrons in the 2s shell and thus, these electrons will repel each...
  29. J

    Atomic Models: Overlapping N Levels & Possible Alternatives

    Have atomic models been proposed that do not have overlapping N levels?
  30. B

    Can intense gravity stop atomic motion ?

    can intense gravity like this in black holes stop atomic motion/jiggling ? if it does , where does the kinetic energy go ? does it radiate before entering a black hole ?
  31. S

    Atomic description of what happens in a capacitor.

    I've examined in lab how a capacitor acts within a circuit. In a case where we charge a capacitor in series with a bulb and then another capacitor, I get the circuit in charging.png. So let's say electrons in the circuit flow from the positive end to the negative end and the circuit flows like...
  32. N

    Inside radius of atomic electron cloud vs Z

    I am interested in knowing if the inside radius of the inner most part of the electron cloud is a constant versus Z. For example is it always the Bohr radius, or does this inner radius change as a function of Z? What is the experimental evidence?
  33. J

    Free-fall atomic model: Bohr with magnetic corrections

    We still often meet Bohr classical atomic model, e.g. for nearly classical Rydberg atoms. However, this model ignores the fact that electron has very strong magnetic moment: is tiny magnet (it wasn't known when Bohr introduced his model). To understand why there are needed corrections, let us...
  34. U

    Atomic number density and mass density

    Hello everyone. I have a problem I can't figure out. Let's say that we start off with UO2 fuel. Knowing the density (and enrichment) we can calculate the number densities of the constituents (i.e. U-238, U-235, U-234, O-16). Suppose now that the fuel is burned to a certain exposure. A...
  35. marcus

    A New Generation of Atomic Clocks

    This was just posted today, and looks interesting http://arxiv.org/pdf/1309.1137.pdf A New Generation of Atomic Clocks: Accuracy and Stability at the 10-18 Level B. J. Bloom et al The exquisite control exhibited over quantum states of individual particles has revolutionized the field of...
  36. A

    Exploring Iron's BCC Atomic Positions with Increasing Atom Numbers

    how do i determine the different atomic positions of iron (bcc) as the number of atom increases.
  37. L

    What Are the Career Opportunities in Atomic Physics?

    Hi, I am having a problem on career choice. I like astrophysics, but I am also interested in atomic physics. What do atomic physicists do as their job, can they get employment in industries?
  38. H

    Ochem - linear combination of atomic orbitals

    1. Homework Statement Draw an LCAO representation of all of the bonding orbitals for C2H2O. Be sure to clearly state the hybridization of the two carbons and the oxygen in addition to drawing the orbital representation. Also show clearly what orbital any unshared pairs occupy. 2...
  39. L

    Why Does Energy Behavior Differ in Particle in a Box Model Versus Bohr's Theory?

    Hi, Please help me I am lost. I particle in a box model , equation for energy show that the energy increases as n increases, but in Borh's theory n^2 is in the denominator showing that as n increase, the energy decrease, I see the condradiction here. Am I right?
  40. S

    Accelerating Atomic Decay Rate of Unstable Elements

    Is there any thing that could, or any way to increase the atomic decay rate of already unstable elements, such as the radio active elements. magnetically or otherwise, even if the thought is only plausible or otherwise theory, I wouldn't mind hearing it. A thought accord to me, what if...
  41. D

    Phase-plane dynamics of an atomic force microscope cantilever.

    Hello, A sinusoidally driven and undisturbed cantilever of an atomic force microscope (AFM) oscillates ideally in a sinusoidal fashion but the motion of the cantilever (time-domain trajectory) can become more complicated when it is disturbed by the inter-atomic forces as the cantilever taps...
  42. P

    Atomic clocks in gravitational field

    In his paper, Chou et. al., 2010 has demonstrated that an atomic clock at the height of our head ticks faster than an atomic clock at the height of our feet. I was thinking that one electromagnetic process can be substituted with any other - so that corresponding atoms in our head tick faster...
  43. A

    Near-resonant atomic transitions

    To excite an electron in the atom from lower state to higher you need an EM field of frequency that matches the energy difference between those levels. How does the near-resonance transition work then? Thanks in advance.
  44. S

    Is an Atomic Computer the Future of High-Speed Processing?

    A thought crossed my mind about the idea of atomic computers. In short, I have no clue as to whether such a thing is feasible, already in the works, or just a bunch of nonsense, which is why I decided to bring it up here and see if anyone could offer some insight into this idea. If so, I’d...
  45. S

    Atomic Structure of Wet Oxidized Silicon

    Hello everyone, I would like to buy some Si wafer with SiO2 layer on it. The manufacturer told me that they obtain the SiO2 with a wet oxidation process. My question is, would this layer be amorphous or crystalline or polycrystalline? Thanks!
  46. S

    Exploring Zeta in Atomic Shells and Quantum Physics

    Hi, Simply, what is "zeta" in atomic shells and what is its relationship with orbital angular momentum (L)? How is it used in quantum physics?
  47. F

    Atomic scattering factor for compounds

    Hi there, I am trying to calculate diffraction efficiencies of a lattice with the coupled wave theory. As material parameters the programm I got needs the atomic scattering factor f1 and f2. (see http://henke.lbl.gov/optical_constants/asf.html for elements) I understood this seems to...
  48. F

    The meaning of a symbol in Atomic Theory

    I happened across this little thing in a formula and I can't find what it stands for in any book/ website :confused: I think it stands for the ground state of an element, but I want to clarify first :smile: The symbol is E0 Its in this formula, which is derived from the energy of an...
  49. D

    2 Atomic Physics questions - Pauli exclusion principle

    Homework Statement Q1. Briefly explain the relevance of the Pauli exclusion principle for the structure of the periodic table of the elements. Q2. What is the maximum number of electrons that can be located in an atomic subshell with quantum numbers n and L? Briefly expain your answer...
  50. U

    How Is the Rydberg Constant Calculated from Photon Absorption Wavelengths?

    Homework Statement The following photon wavelengths are observed in absorption at room temperature from an ionized atomic gas with a single electron orbiting the nucleus: λ= 13:5 nm, 11:4 nm, 10:8 nm. Use this data to determine the effective Rydberg constant and the nuclear charge...
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