Atomic Definition and 853 Threads

  1. L

    Eigenvalues of positions in atomic orbitals

    Let's take a hydrogen atom with a single electron. How many eigenvalues of position can it form (assuming you put it the atom in an x, y, z coordinate)? like 1 billion possible position eigenvalues? Is it continuous number like 1.1, 1.2, 1.3 or quantized? and either case, how many eigenvalues...
  2. Shri13

    Photonic vacuum and atomic stability

    Hi friends, this is my third post of my curiosity. :woot: First of all a photonic vacuum (as defined by me) is a region of space where there doesn't exist any type of photons or EM radiations ( those too which are beyond the detection of our present tech... i.e. including each and every...
  3. mukul

    Do low atomic numbers not obey Moseley's law?

    Helium has k-alpha of 24.5 eV whereas if we derive it using Moseley's law, then it is supposed to be 10.2 eV Also I then looked into many sources and found that Moseley's graph talks about elements having z>=10 only Later I found in few sources that the assumption that "one electron shields...
  4. S

    Can I make a banana from nothing?

    Excuse the simplified question title. I have very little knowledge in the world of organic chemistry, and chemistry alone. If I looked at the composition of banana (atomically), and then I got a little jar full of every element that is necessary to a banana's composition, could I make a...
  5. S

    Gold Atom Count in O-Ring: 10.4x10^21

    Homework Statement A golf O-ring is used to form a gastight seal in a high-vacuum chamber. The ring is formed from a 100-mm length of 1.5-mm-diameter wire. Calculate the number of gold atoms in the O-ring. Homework Equations Volume of cylinder = PI*h*r^2 The Attempt at a Solution I got the...
  6. J

    Atomic clock: energy between two levels

    Homework Statement With the atomic clock a second is defined as the time it takes for EM radiation to oscillate 9192631770 times, which equals the energy gap between two energy levels of a caesium-133 atom. Note: it's a translation and the term used with the oscillation is "oscillation periods"...
  7. F

    How can two atomic orbitals with the same n value be orthogonal?

    I am wondering how two orbitals of same n values can be orthogonal, for example how are a 2s and 3s orbital orthogonal? What I understand is a property of orthogonality is the product of the two wave functions integrate to zero over all space. I tried to look at this graphically and categorize...
  8. C

    Propelling force of Atomic Blast?

    Assuming a spaceship could be impervious to the damaging effects of a nearby atomic blast, what speed could the ship reach in space due to the explosion? Interested to know how to figure that.
  9. S

    Books on Atomic Structure, Chemical Bonding, Quantum for Beginners

    Hi all! I would like to ask your help! I am a rookie in the subject. I have to admit i don't exactly interested in the mathematical way. I really don't have the "basic" advanced math which would needed it. :) Look at me if i would be a high school physics and chemistry teacher whose imaginary...
  10. Matt atkinson

    Why Are There More Energy Levels in Silicon's 3p4p Configuration Than in 3p²?

    Homework Statement Silicon has the configuration [Mg] ##3p^2##. Explain why there are more L, S, J levels for the ##3p4p## configuration than in the ##3p^2## configuration. Homework EquationsThe Attempt at a Solution My thought is because in the ##3p^2## subshell you have less variations of...
  11. R

    Nuclear fission in an atomic bomb

    A person said: "However uranium-235 (U235) makes up only 0.72% of normal uranium metal and has to be separated from the remainder (mostlyuranium-238) in special factories which makes uranium-235 (U-235) a little more expensive. An uranium-235 (U-235) atomic has three neutrons less than an...
  12. Chronos

    Using atomic clocks for gravitational wave detection

    This paper, http://arxiv.org/abs/1501.00996, proposes using atomic clocks for gravitational wave detection. It sounds similar to other ideas involving pulsar timing experiments. The twist here is utilizing satellites to provide a wide base for improved sensitivity. Sounds like an inexpensive...
  13. Shablong

    Did Newton assume matter was atomic?

    Hello all, I was talking to a friend of mine earlier explaining why a force acts as if all the mass is concentrated at the center of mass. I know of no other proof than taking the time derivatives of the center of mass. Seeing as this was long before definitive proof of the atomic structure of...
  14. J

    Why is the relative atomic mass always changing?

    And why the range of changing is different when we use different atoms as standards?
  15. J

    Why hydrogen is not used to compare the relative atomic mass

    Is that because of some historical reasons or E=mc2(i mean something about binding energy)?
  16. A

    What's the Mean Free Path of a Gas Atom?

    http://www.pluggakuten.se/wiki/images/3/3e/Prov221.JPG Solution
  17. P

    Unravelling the Mystery of Rare Gases and Binding Energy

    Hi! I saw something on my lecture notes that I don't really understand. It reads "Rare gases have filled s and p-sub-shells, which leads to a spherically symmetric charge distribution. Since electrons are indistinguishable they take on a common wavefunction. The point is that this results in a...
  18. M

    Please suggest alternatives to this Atomic Physics book

    Hi, I am currently taking a course on Atomic and Molecular Physics, and the book for the course is https://www.amazon.com/dp/3642102972/?tag=pfamazon01-20. The course is based on this book. The Amazon link will allow one to preview the table of contents. The school library only has copies of...
  19. V

    Paschen notation in atomic spectroscopy

    I was trying to understand electronic excitation in Xenon. Most of the research journals are denoting different excitation levels in terms of Paschen notation, which i think, is generally used to represent excited states of inert gases. Can someone please explain how to use this paschen notation...
  20. G

    An atomic clock and a normal clock

    Two clocks in a spaceship floating though space at 99% the speed of light. One is a atomic clock and uses light and mirrors to measure time, the other clock uses cogs and gears like a conventional clock. From the perspective from inside the ship both clocks tick and tock at the usual rate...
  21. bearcharge

    Pointless in talking about atomic term for a certain micro-state?

    I'm a chemist trying to understand atomic term symbol. If we list all the micro-states of certain multi-electron configuration, these micro-states can be grouped into several certain terms characterized by L and S. In other words, when we compute the ML and MS for each of the micro-state, they...
  22. P

    Spin-orbit Interaction & Degenerate Perturbation Theory

    Hello! This is my first time posting, so please correct me if I have done anything incorrectly. There's something that I don't understand about the spin-orbit interaction. First of all I know that [\hat{S} \cdot \hat{L}, \hat{L_z}] \ne 0 [\hat{S} \cdot \hat{L}, \hat{S_z}] \ne 0 so this means...
  23. U

    What Transitions Create Calcium's Emission Lines at These Wavelengths?

    Homework Statement Strong emission lines from calcium were observed at ##422.7nm##, ##610.3nm##, ##612.3nm##, ##616.3nm##, ##1034.9nm##, from transitions between ##4s^2##, ##4s5s## and ##4s4p##. The transition of ##422.7nm## was also observed at absorption. The singlet-triplet splitting of...
  24. L

    Need help using the atomic form factor

    Homework Statement I need to calculate interference peaks using the atomic form factor for several lattice types for a lab report. I was given the expected answers but told I should also be able to calculate them.Expected results for rocksalt (eg NaCl): h+k+l = 2n fh+k+l = 4(fa+fb) h+k+l =...
  25. Muthumanimaran

    Molar Mass & Atomic Number: Explained

    How molar mass and atomic number are interrelated? Give me a detailed explanation. How to find molecular mass and molar mass for molecules?
  26. L

    Atomic Form Factor Homework: NaCl, LiF, GaP, Si

    Homework Statement I am trying to calculate the atomic form factor for various crystals (NaCl, LiF, GaP, Si) in an x-ray diffraction experiment. There seems to be very little information on this topic anywhere.Homework Equations [/B] I understand how to derive the geometric form factor Sk =...
  27. C

    Difference between fusion and fission

    Hi there, Sorry if thisis a stupid question its just been bugging me for a while and I am not a scientist as such so need help with the answer... nuclear fission is where two atoms collide and release energy yes? nuclear fusion is where two atoms combine to release energy and a new isotope...
  28. skate_nerd

    Small question about atomic form factor calculation

    Homework Statement This problem just has me find an atomic form factor for some arbitrary basis atom in a bravais lattice where the electron wave function is given (it has a dependence on the Bohr radius in an exponential). I calculated the form factor (a very long, nasty integral that...
  29. V

    Dimensional analysis - atomic bomb explosion radius

    Homework Statement :[/B] An atomic explosion can be approximated as the release of a large amount of energy ##E## from a point source. The explosion results in an expanding spherical fireball bounded by powerful shock wave. Let ##R## be the radius of the shock wave and assume that...
  30. O

    Finding Atomic Mass Unit by Subatomic Particles

    If one atomic mass unit is 1/12 of a C-12 atom, so 1 amu must be; 1 Amu = 1/2 ( Mass of proton + Mass of neutron + Mass of electron ) But the equation gives the answers that 1 amu is 1,6737 10^(-27) kg, which is different than the internet says I am using very sensitive values for the...
  31. A

    Engineering Nuke physics vs atomic physics vs nuke engineering

    Okay can I first start of by saying sorry if there are any gramatical errors or mis-spellings I've got dyslexia and, well, sometimes things can get messy! So I have been really interested in Physics since I was really young, mainly in things like astrophysics and questioning why things happen...
  32. 1

    Chemistry Relationship between Atomic PPM and Mole

    Homework Statement Why does 25 atomic ppm oxygen mean 25 moles of oxygen in 1e6 mole Fe? Homework Equations # = mol*Avo The Attempt at a Solution I understand the ppm (parts per million) part. Hence why 25 ppm means 25:1e6. What I do not understand is how they go from atomic to...
  33. A

    Are atomic orbitals electron standing waves?

    Do electrons really exist as standing waves in an atom? If so, are these standing waves what are known as atomic orbitals?
  34. P

    Atomic Nucleus Spin: Theory & Explanation

    Is there a theoretical basis for the spin of the nucleus of an arbitrary atom? I'm looking at this website: http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/nspin.html
  35. S

    How does light behave when passing through glass or water?

    When light passes in glass, water etc then velocity is reduced and direction changes HOW?
  36. S

    Helium Atomic Structure: Ionization Speed Compared to Air

    Would helium take less time to ionize than air, because it expand faster when heated up?
  37. H

    Determination of atomic bases in unit cell using Wien2k

    After specifying the primitive vectors of a structure namely (a,b,c) in Wien2k, one has to specify locations of atoms in unit cell.There are three components X,Y,Z which determine the atom location. I want to know whether "X,Y,Z components" are corresponding to vectors a,b,c or they are...
  38. N

    At the atomic level why is it harmful to stand in an electric field?

    Homework Statement I was reading on Faraday's Cage and how if we are inside a conductor (car) we will not be harmed by the electric field strength of lightning if it strikes the car. (because conductors always have an E = 0 inside them because excess charge will always rapidly move to the...
  39. K

    Atomic Number & Orbital Energy: Explained

    My book here says that ' Despite the shielding of the outer electrons from the nucleus by the inner shell electrons, the attractive force experienced by the outer shell electrons increases with increase of nuclear charge. In other words, the energy of interaction between the nucleus and electron...
  40. T

    Atomic excitation via photon absorption

    Hi guys! I have come across a problem I can't seem to wrap my head around. I've learned that E.M. radiation can be propagated by discrete packets of energy , photons. Is the energy of each photon discrete, or can it have a continuous range of energies depending on its frequency? I would be...
  41. K

    Can anyone name this children's history of atomic science?

    This has been bugging me for a year or so - sorry if this is off topic, but would anyone on the forum be able to name a book on atomic physics I read as a child? It was a non-fiction, illustrated picture book I read as in the late 70's or very early 80's, giving the history of atomic science...
  42. K

    Energy of atomic orbitals in multielectron system

    although the distance from the nucleus and shielding effect [due to more angular volume] is more for 4s orbital than a 3d orbital ,but yet the energy for a 3d orbital is more than 4s orbital, why?
  43. C

    Atomic Vibrations & Time Dilation: The Reality Behind Our Perception

    We measure time based off of atomic vibrations, so time dilation from gravity and velocity are nothing more than pressure applied to the atoms, slowing their vibrations. This isn't an accurate measure of what we consider time, but more of a measure of the reaction of atomic vibrations under...
  44. N

    Bohr's atomic model and Bohr and Rydberg equations

    Hello, well, I am totally new to this section of physics so my question may sound ridiculous, but here it is: When I was reading about the Bohr's atomic model, I learned about the Bohr and Rydberg equations (E=-2,18*10^18*Z^2/n^2 J and 1/λ=RZ^2(1/n1^2-1/n2^2) as well as their proofs. Then I...
  45. Symmetry777

    Unraveling the Atomic Spin: Understanding the Building Blocks of Matter

    What gives an atom its atomic spin?
  46. S

    Can We Truly Touch Anything at the Atomic Scale?

    I know this is a very common question but I've been seaching in forums all the time and couldn't find a clear answer. So quantum physics say that we can't actually "touch" anything because of our atoms( we're all made of atoms and they repel each other). correct me if I am wrong,please.. atoms...
  47. T

    Advanced atomic physx: From Liouville Equation to the Bloch equations

    This question was on Stackexchange, and no one was able to solve it. So now I'm posting it here, and I wish someone could help. I'm trying to derive the Bloch equations[1] from the Liouville equation[2]. This should be possible according to this paper[3], where it discusses higher order Bloch...
  48. S

    Can One Electron Make Two Transitions in a Row?

    Homework Statement Three photons coming from excited atomic hydrogen sample are picked up. Their energies are 12.1 eV, 10.2 eV and 1.9 eV. These photons must come from? A)two or three atoms B)single atom C)three atoms D)two atoms The Attempt at a Solution By solving it i got single...
  49. D

    Is this the correct way to estimate the natural lifetime of an atomic state?

    Hi there, I've just been having a little trouble with this short question from a past exam paper... Homework Statement "An atomic state has a dominant decay mode which produces an emission line of wavelength 6 \times 10^{-7} m and natural width 10^{-13} m . Estimate it's natural lifetime...
  50. C

    Atomic Model of Hadrons mass of excited particles

    So in a lecture I'm reading up on we are given questions to answer during the lectures with no answers, and for this particular lecture the answer has been omitted and it is in none of our textbooks. But basically it says that a proton and a sigma plus, both have the same quark composition...
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