Atomic Definition and 812 Threads

  1. S

    Converging the Hamiltonian in Atomic Units?

    Homework Statement So the question is I have to use some trial function of the form \sum c_if_i to approximate the energy of hydrogen atom where f_i=e^{-ar} for some number a (positive real number). Note that r is in atomic unit. Homework Equations Because r is in atomic unit, I think I should...
  2. B

    Atomic particle g-factor relationship?

    The g-factor of an electron (-2.002) added to the g-factor of a proton (-3.826) approximately equals the negative g-factor value of a proton (5.585). Ge + Gn = -5.828 Is there any significance in this?
  3. P

    Finding the atomic makeup of a substance

    Hey all, This is actually my first post on this forum but I have been reading it for a few months now. Anyway, I'm sure the title of this thread might be confusing but this question has been bugging me for years now and I'm sure I'm missing something quite elementary. My question has to...
  4. M

    Why does Atomic Mass Differ from # of Protons & Neutrons?

    Why atomic mass doesn't match the number of protons and neutrons in it? for example mercury mass is 200 gmol but it has only 80 protons and 80 neutrons. From where does 40 gmol come from?
  5. X

    Balmer series for atomic hydrogen lie

    Homework Statement The first few lines of the Balmer series for atomic hydrogen lie at the wavelengths λ = 656.46, 486.27, 434.17, 410.29nm, ... Find a value for RH, the Rydberg constant for hydrogen. The ionization energy I is the minimum energy required to remove the electron. Find it from...
  6. P

    What is the Virial Theorem and its significance in Atomic Physics?

    So my Atomic Physics professor today was talking about some called the "Virial theorem" in relation to Bohr Model of the H-atom, which in my 5 years of college physics I had never heard of >_<;; . It turns out that I had seen equations that use concept of the Potential "==" Kinetic Energy, I...
  7. M

    Derivation of the atomic form factor

    My book defines the atomic form factor as \int dV n_{j}(\vec{r})e^{-i \vec{G} \bullet \vec{r}}. where n(r) is the electron density of the jth atom at r, and G is the reciprocal lattice vector. It says the above expression is equal to 2 \pi \int dr r^{2} d(cos \alpha) n_{j}(r) e^{-iGr cos...
  8. jaketodd

    Atomic electron wave frequencies

    Hi, I am wondering what sort of frequencies electrons have in atoms at different energy levels. When I say frequency, I'm *not* talking about the frequency of the orbiting motion. I am wondering what the electron wave oscillation frequencies are at the different energy levels. A couple...
  9. mnb96

    Limits of classical views of the atomic structure

    Hello, this might be a trivial question for many of you. I would like to know what are the simplest phenomena/experiments, if any, (and perhaps the first historically) that contradict the assumption that subatomic particles like electrons, protons, neutrons..., can be thought of as "small...
  10. J

    Atomic Fractions: Calculating Xc & Xo in H2, H2O & CO2

    Hi Guys, I have a bit of a problem with some course work please help: The question is: Determine the atomic fractions Xc and Xo (carbon and oxygen) for the following gas composition at room temperature: 50% H2, 30% H2O, 20% CO2 I am sure you need to work out the partial pressures for...
  11. C

    What Makes Atoms the Key to Understanding Our Universe?

    I find it remarkable that physicists are sometimes willing to take “the anthropic principle” seriously, in any of its forms, since its explanatory power at the physical level is nil. Okay, say the universe is structured the way it is just so it can support conscious observers. That tells us...
  12. A

    Atomic radius by dimensional analysis

    Hi, So according to the Thomas-Fermi theory, the formula for atomic radius is R=Z^(-1/3)*(hbar ^2)/m*e^2. (in other words Z^(-1/3) times the Bohr radius) While the total energy has a Z^(7/3) dependence. I need to get this from dimensional analysis. I can get the dependence on h, m, and...
  13. T

    Correlation between electronic band structure of an atomic species

    Hii, I was wondering whether there is any correlation between the energy eigenvalues of a single atom (say He) with the electronic band structure of a collection of He atoms. for example, for He atoms the lowest energy would be the ground state, with 2 electrons. So will the lowest band for a...
  14. H

    Calculating the explosive yield of an atomic bomb

    Homework Statement I'm writing a paper on the Manhattan Project, and as part of this paper I am asked to show: "... calculations that can help illustrate the explosive power of an atomic bomb compared to ordinary explosives."Homework Equations Released energy per fission: Q = \Deltam * c2 The...
  15. E

    What Quotes Capture the Legacy of the Atomic Bomb?

    "Told science" Hi guys! I am going to take part in a literature project, which is called "told science". You have to write a scientific eassy such as a story. For this year I was wondering to write down something about the atomic bomb. My idea was to write the best quotation on atomic bomb in...
  16. S

    Nuclear Atomic Model: Definition & Overview

    What is meant by nuclear atomic model?
  17. L

    How does atomic structure relate to how well things share energy.

    Like, let's say substance A, in the sun, is very hot. After the sun goes down, it stays hot, but after awhile it becomes cold. Element B, in the sun, is also very hot, but after the sun goes out, it basically becomes cold immediately. Why is this?
  18. I

    How Do You Calculate the Landé g Factor for sd Configuration in jj Coupling?

    This is rather a straightforward question I believe, but somehow I'm not sure about the wording of it... Homework Statement Calculate g value (Landé g factor) for sd configuration in jj coupling. Homework Equations g = 1 + \frac{J(J+1) - L(L+1) + S(S+1)}{2J(J+1)} The Attempt...
  19. P

    Why Do Textbooks Still Use Bohr's Atomic Theory Despite Its Limitations?

    1. Isn't it the Bohr atomic theory is proven incorrect, why some textbook even that publish in 2007 still use it to explain about electron movement? Isn't it should be using SPDF theory? 2. What is meant by satellite valley? 3. How is electron move in atom if not circulate in an orbital? 4...
  20. T

    Calculating Approximate Atomic Mass of Lead | Isotopes of Pb and Percent by Mass

    Homework Statement 1. The Table below lists the isotopes of Pb and their percent by mass: Isotope % Mass 82p, 122n 1.37% 82p, 124n 26.25% 82p, 125n 20.82% 82p, 126n 51.55%(a) Using these data, calculate the approximate atomic mass...
  21. S

    Atomic mass unit and Molar mass

    Hi My textbook states that say 50 amu/atom = 50 g/mol. Which does not really make any sense. I am not sure how to get the atom unit. Since on wikipedia it says u = Molar-mass/Na Molar-mass(g/mol) = u*Na I also know that 1gram/Na = 1u
  22. K

    Can gas density be permanently altered and what influences it?

    Can the density of gas be changed for good, or is the change just temporary? And what increases density in gases?
  23. H

    Where can I find images of atomic energy level diagrams for chemical elements?

    Hi, I'm having problem about Atomic energy levels. Who can help me find Images about Atomic energy levels diagrams of chemical elements. Thanks^^. Example: Atomic energy level diagram of Hg: [PLAIN]http://ca8.upanh.com/15.290.19566358.Z7p0/fig1.gif You can contact me. I'm Hoang An
  24. N

    What is the method for calculating atomic mass from isotopes?

    hi i was wondering if anybody could help me? for calculating if there's a missing part how do i solve it ? i have a picture ... how would i figure out the third part ..?
  25. P

    Atomic Physics - Xrays and energy

    Homework Statement 5 The energy levels of a molybdenum atom are approximately: K shell ….. – 20.00 KeV L shell …... – 2.52 KeV M shell …... – 0.23 KeV i) Estimate the energy of the Kα, K\beta and Lα x-ray emissions. ii) What are the wavelengths of...
  26. somasimple

    What are the common atomic radii used for chemical pictures?

    Hi all, What are the common atomic radii that are used for drawing chemical pictures? Is it the ionic or calculated or? Thanks.
  27. B

    Quantum physics- atomic states

    Homework Statement Give the full designation (e.g. 3P0) for all possible singlet, doublet, triplet and quartet S, P and D atomic states. The Attempt at a Solution I don't understand this question at all! Up to which values does the angular momentum (supscript) and multiplicity...
  28. X

    Hydrogen vs Atomic: Nuclear Fission vs Fusion Explained | Damage Comparison

    Homework Statement What is the difference between nuclear fission and nuclear fusion? After answering the question proceed on to answer the next question Between Hydrogen Bomb and Atomic Bomb, which bomb causes more damage. provide you answer with reasons. Homework Equations Nuclear...
  29. K

    How to Calculate the Atomic Mass of Contaminated Iodine?

    Homework Statement Naturally occurring iodine has an atomic mass of 126.9045. A 12.3849-g sample of iodine is accidentally contaminated with 1.00070 g of ,129I a synthetic radioisotope of iodine used in the treatment of certain diseases of the thyroid gland. The mass of129I is 128.9050 ...
  30. R

    Atomic Level Time Dilation Resources

    Hi, I'm looking for any resources explaining time dilation at the atomic level. I can't find anything on it sooo If anyone could please refer me that would be helpful. kind regards
  31. T

    Question about Rutherford atomic model

    Rutherford postulated that the electrons are moving around the nucleus of the atom in circular trajectories, right? My professor said that or I believe in it or there is no more chemistry to study, because this does not agree with some law of Maxwell's theory of electromagnetism. He said...
  32. M

    Quantum Energy levels in atomic, molecular, nuclear and solid state physics

    Homework Statement Greetings everyone I have been been asked to write a 10 page essay on Quantum Energy levels in atomic, molecular, nuclear and solid state physics. My problem is that this is such a huge topic and my knowledge of quantum energy levels and solid state physics is limited...
  33. C

    A description of fire at an atomic level

    I'm trying to understand what fire is at an atomic level. I'd appreciate it if you guys could correct me where I am wrong and fill in any gaps. 1: When you heat an object it introduces energy. 2: This energy causes the atoms in the object to jiggle around. 3: At some point introducing the...
  34. T

    Atomic Structure: Is It Necessary to Assume Orbits Are Circular?

    Please help me in clearing my basic doubt We all know that positive charges are concentrated at the centre of the atom , known as nucleus and electrons revolves around the nucleus in orbits. Is it necessary to assume that orbits are circular ?
  35. C

    The Mysteries of Atomic Clocks

    So I am reading about how an atomic clock works , So they shoot microwaves at cesium atoms and the right microwaves will cause an electron to jump up to the next energy level , are they using this to tune the microwave laser so they know what the frequency of the laser is . and when they...
  36. M

    What is the relationship between atomic density and mass density in aluminum?

    Can anyone help. How do I calculate mass density of aluminium, given the atomic density of 6.04 X 10^22. I understand that Density = Mass/Volume. but the question confuses me. Thanks
  37. Saladsamurai

    Chemistry Atomic Ratio and Ratio of Mole Fractions

    Homework Statement Hi folks! :smile: This is just a conceptual question that has arisen during some reading. At one point the author states that for the reaction: CO_2 \leftrightharpoons X_{CO}CO + X_{CO_2}CO_2 + X_{O_2}O_2 where X is the mole fraction of each component at equilibrium...
  38. R

    Shifting atomic spectrum

    Can the absorption spectrum of an atom be shifted significantly using electric or magnetic fields ? such that to turn red to blue or something ? Another question, can atoms be excited to a certain energy level by applying external fields only with calculated energy ? thanks
  39. D

    What is the relationship between latitude and the accuracy of an atomic clock?

    Atomic clock should record different time depending on their geo location: different latitude -> different rotation speed. Question: The most precise time on Earth - where is it valid? On what Latitude?
  40. R

    Nuclear physics: neutral atomic mass vs. atomic mass

    Homework Statement I am preparing a presentation on nuclear reactor technology. To demonstrate the mass-energy equivalence, I am trying to calculate the binding energy of some heavier isotopes. The problem is that, when I substitute the values that I have into the equation, I get a...
  41. K

    Find equilibrium bond potential, given energy as a function of atomic separation

    Homework Statement Given that the total cohesive energy, U, in an ionic crystal as a function of nearest neighbor distance, R, between two ions +e and -e is given by: U(R) = \frac{A}{R^n} - \frac{\alpha e^2}{4 \pi \epsilon R} show that at equilibrium: U(R) = \frac{\alpha e^2}{4 \pi...
  42. H

    Atomic gas and Semiconductor Lasers.

    Hi, I want to know what the important quantitative differences between the light produced by an atomic gas laser and that produced by a semiconductor laser are? I know that produced my atomic gas lasers are low power but high collimation, but semiconductor lasers seem to have higher power...
  43. S

    Determination of Atomic Masses help

    what i did: 27.40 * 0.781 = 21.4 52.9 * 0.811 = 42.9 62.6 * 0.856 = 53.59 there is a hint that says i have no idea how to get the common factor with those numbers.. btw i had no idea where i can post this in here so i posted here :X
  44. M

    Atomic Paramagnetism: Understanding m_j Sublevels

    Hey everyone, I've noticed that when paramagnetism is derived in the context of stat mech, we only consider the energy levels of the perturbation. Essentially, we take the fine structure of hydrogen, and we perturb it with a B-field, causing the weak zeeman effect to split the energy levels...
  45. M

    Solving Problems in Quantum Mechanics, Stat Mech & Atomic Physics

    Are there any other good books such as LIM series which include solved problems on QM,Stat Mech & atomic physics ?
  46. F

    Physicists capture first images of atomic spin

    I can't even claim to understand 'spin' as a property (even after reading that big thread about it :P) but I'm sure with the amount of discussion that generated, this could be worth talking about http://www.ohio.edu/research/communications/spin.cfm
  47. A

    Calculating Wavelength Using Atomic Emission Spectra and Balmer Series Equation

    in an experiment we looked through the diffraction grating to see the spectrum made by a helium lamp. we measured the distance along the meter stick to the point where we saw each color. based on that distance how would you calculate the wavelength of the light that was seen? would you...
  48. M

    Is Gas-Liquid Diffusion Applicable for Precursor Atoms in a Molten Salt Reactor?

    How shall diffusion of precursor atoms be treated if the core is in liquios state(as is MSR)[I mean regarding to its low volumetric density, shall we treat it as gas-liquid diffusion and is diffusion approximation or even transport theory valid for it anymore, what's the meaning of state space...
  49. N

    Calculating maximum amplitude of atomic vibrations

    Is it possible to predict theoretically the maximum amplitude of vibration that atoms of a metallic species, like Copper, will exhibit at a given temperature?
  50. R

    What Makes Ferromagnetic Materials Unique in Quantum Magnetism?

    I heard that the reason why we can't put our hands through a wall (or such a thing) is because of atomic electromagnetic forces pushing things away from each other (since after all, things are mostly empty space, and only seem solid because of the scale). I also heard that that is the same force...
Back
Top