Atom Definition and 999 Threads

The name Atom applies to a pair of related Web standards. The Atom Syndication Format is an XML language used for web feeds, while the Atom Publishing Protocol (AtomPub or APP) is a simple HTTP-based protocol for creating and updating web resources.Web feeds allow software programs to check for updates published on a website. To provide a web feed, the site owner may use specialized software (such as a content management system) that publishes a list (or "feed") of recent articles or content in a standardized, machine-readable format. The feed can then be downloaded by programs that use it, like websites that syndicate content from the feed, or by feed reader programs that allow internet users to subscribe to feeds and view their content.
A feed contains entries, which may be headlines, full-text articles, excerpts, summaries or links to content on a website along with various metadata.
The Atom format was developed as an alternative to RSS. Ben Trott, an advocate of the new format that became Atom, believed that RSS had limitations and flaws—such as lack of on-going innovation and its necessity to remain backward compatible—and that there were advantages to a fresh design.Proponents of the new format formed the IETF Atom Publishing Format and Protocol Workgroup. The Atom Syndication Format was published as an IETF proposed standard in RFC 4287 (December 2005), and the Atom Publishing Protocol was published as RFC 5023 (October 2007).

View More On Wikipedia.org
Recent contents Top users
  1. A

    Normalization of Radial wavefunction of hydrogen atom

    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...
  2. S

    Prove that the Bohr hydrogen atom approaches classical conditions when [..]

    "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 –...
  3. J

    Why is a hydrogen atom lighter than a electron and a proton

    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...
  4. K

    Interactions between Photons and Atoms in the Electromagnetic Spectrum

    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...
  5. D

    Hyperfine splitting in Hydrogen atom

    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...
  6. A

    Why does the normal hydrogen atom lack a neutron

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

    How close must the wavelength of a photon be for an atom to absorb it?

    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?
  8. J

    Year 12: Cambridge Physics Problem (Distance of O atom in atmosphere)

    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...
  9. E

    Expanding Spacetime - Inside an Atom?

    I think that it is correct to say that everywhere, spacetime is expanding. Is it expanding within the radius of electrons within atoms? Are the radii getting larger over time? I believe it correct that the distance from the nucleus to an electron exceeds the diameter of either one by...
  10. N

    Can the Quantization Axis of an Atom Affect its Spectral Emission?

    Hi Please see the attached picture. It shows an atom, the filled black circle, which consists of a J=0 level (with m=0 sublevel) and J'=1 (with m' = +/- 1 sublevels). From the left is a nearly monochromatic laser impinging on the atom, which is linearly polarized along the same direction of...
  11. M

    If the bohr model of the atom is correct

    so imagine a hyper-classical scenario. A single point elecrron is orbiting a point nucleus. No other charged objects are nearby. There is no em radiation from the electron. The electron orbits the nucleus in perfect circular motion. Zero orbital precession, zero uncertainty in the...
  12. K

    Unlocking Quantum Numbers for Lithium Atom

    Homework Statement Lithium has an atomic number Z = 3. Two of its electrons have the quantum numbers {n, L, m{l}, m{s}} = {1,0,0,+1/2} and {1,0,0,-1/2}. Write down the corresponding set of quantum numbers for the third electron in the lowest energy state of the Li atom. Briefly explain the...
  13. R

    Does amount of electrons orbiting an atom effect rate of radioactive decay?

    Do ions have a measurably different rate then their neutral counterpart or does the rate of radioactive decay and electrons have no correlation? Also, when a source states an elements half life is that the same for all of its isotopes?
  14. S

    State of electron in hydrogen atom

    The term (E-V) which stands for kinetic energy is used in Schrodinger equation.Kinetic energy of electron needs motion and fixed path which leads to the conclusion that electron is moving around the proton in orbits and is not spread out because derivation of Schrodinger equation is based on...
  15. N

    An alpha particle is fired at a uranium atom

    Homework Statement "If an alpha particle is fired straight at the nucleus of an uranium atom (q = 92e), at a velocity of 5 x 10^5 m/s, how close will it get to the uranium nucleus? Homework Equations Ek = (mv^2)/2 Ee = (kq1q2)/d The Attempt at a Solution Since the alpha particle and...
  16. K

    How much energy does the nuclear fission in one uranium atom give?

    Does it give a lot or is nuclear fission only powerful when you have a large quantity?
  17. S

    Delocalization of electron in hydrogen atom

    if delocalization of electron in hydrogen atom means that it is spread out upto infinity it means that infinite time is required for the electron to be localized when hydrogen atom is ionized.Is it so?
  18. K

    Considering volume of atom , what radius

    do you consider Covalent radius, Van der Waals radius or atomic radius?
  19. R

    Does diameter of a stable atom ever increase or decrease?

    in a chunk of a pure element like iron-would the outside diameter of the the last electron shell ever naturally change from picosecond to picosecond?
  20. johann1301

    Is the octet rule, important to the atom?

    Can an atom "give away" or "steal from another" an electron AND become an ion just to "satisfy" the Octet rule? Does an atom "prefer" to have 8 electrons in the outer shell MORE then it "wants" a neutral charge(not be an ion)? I imagine this varies from element to element. The elements i am...
  21. A

    Can electron revolving around atom become source of gravity.?

    we know electron revolves around nucleus at nearly (1/100)th of light speed..does this mean electron as very high relativistic mass such that It can become local source of gravity..but this is not the case..why is this so.?
  22. K

    Normalizing etc. Wavefunction of hydrogen atom

    Homework Statement Find the constant A such that the equation \psi(r,\theta,\varphi)=\sqrt{6\pi}A\sqrt{r}e^{-r/a} Wich describes one electron in a hydrogenatom, is normalized The Attempt at a Solution I figured this equation is seperable in the form...
  23. C

    Different between L^2 and L in Hydrogen atom

    I'm here got a small question, what is the different between L2 and L for the hydrogen atom. Do L2 means total angular momentum and L means angular momentum?:confused: Given that L2=l(l+1)ℏ2 and L=(√l(l+1))ℏ THX :smile:
  24. F

    Hydrogen Atom in Uniform Electric Field

    I just did exercise 1.22 in Modern Quantum Chemistry by Szabo and Ostlund. This is a practice problem about linear variational method. ---------------------------------------------------------------------------------------- Question: The Schrodinger equation(in atomic units) for a hydrogen atom...
  25. M

    Quation about term symbols: N atom

    So the term symbol for the nitrogen atom is 4S3/2 This means L=0, S=3/2, hence J=3/2. My question is that if S=3/2 than this is a quartet, meaning there are four levels, yet I only ever see one state listed on energy diagrams? What gives? Obviously, I'm still trying to learn term symbols Are...
  26. A

    Whats potential energy of a electron left in free space outside atom.?

    how does this change with introduction of another charge in its vicinity suddenly..and how does this vary as both charges repel each other after introduction of like charge.. btw I even wonder whether a electron which is outside a atom is in form of wave or particle..hope my questions are...
  27. Z

    Number of collisions/sec for a gas atom

    Homework Statement Consider a single ideal gas atom bouncing between two opposite faces of a cubic container, with sides of length l. Using m for the mass of the gas atom and Vx (V sub x) for the velocity component, give an expression for the number of collisions per second the atom makes...
  28. F

    Comparing Dirac and Schrodinger Equations for the Hydrogen Atom

    The Schrodinger equation solved for the hydrogen atom gave good agreement with spectral lines, except for line doublets. To account for these electron spin theory was grafted onto the theory, despite the problem of electron being a point particle. In 1928 Dirac gives his different answer...
  29. I

    How to Calculate Atom Economy?

    To work out the answer to this question, do I just find the total Mr of the products and divide it by the total Mr of the reactants (and then multiply by 100, and pick the biggest percentage?) Cheers
  30. B

    What is the uncertainty speed of a hydrogen atom inside a virus?

    What is the uncertainty speed of a hydrogen atom inside a virus? Even though the vaue of uncertainty in position is not given. Any help on this would be greatly appreciated. Thanks!
  31. M

    Acceleration of an electron held at 1m from the nucleus of an Uranium atom.

    Homework Statement An electron is held fixed at a distance of 1 m from the nucleus of a uranium atom (Z = 92). If the electron is then released, what is the magnitude of its initial acceleration? Homework Equations I am not sure which kinematic equation that I should use...
  32. A

    Relativistic Bohr Atom and MacLaurin Series

    Homework Statement By expanding a MacLaurin Series show that E_{n}=\epsilon_{n} - \mu c^{2} = - \frac{w_{0}Z^{2}}{n^{2}}[1+\frac{\alpha^{2} Z^{2}}{n}(\frac{1}{k}-\frac{3}{4n})] Homework Equations Through a lengthy derivation I arrived at \epsilon_{n}=\frac{\mu...
  33. K

    Taking a proton out of the atom.

    Now let's say you have a mercury atom that has an atomic number of 80 , now let's say you take out a proton put of the nucleus by using a a lot of energy(nuclear binding energy). Now won't taking the proton out , turn it into a gold atom since gold has an atomic number of 79. ?
  34. B

    The ionization temperature of helium atom

    Homework Statement It is known that the ionization temperature of hydrogen is T. Then, estimate the ionization temperature of the helium atom in terms of T. Assume that Bohr's theory is applicable, that is, All the electrons are occupying hydrogenic levels. By ionization temperature, we mean...
  35. N

    Liouville's theorem and atom optics

    Hi Say I have an oven, from which atoms are effusing through a very small aperture. By "small" I mean such that it does not disturb the thermal equilibrium of the atoms. Now say I choose to e.g. shine laser light onto the atoms transversely to the direction from which the atoms emerge out of...
  36. E

    Use the density of the liquid to estimate the radius of a neon atom.

    Homework Statement Neon is a monatomic gas; Density = 0.900 kg.m-3 Pressure = 1 atm Temperature = 273K. Density of liquid neon = 1207 kg.m-3 (i) Calculate the volume occupied by one gram mole of neon at a temperature of 273 K and a pressure of 1 atm. (ii) Determine the atomic...
  37. Y

    Calculate <x^2> for Hydrogen Atom Ground State | Symmetry Method

    Homework Statement The problem (4.13 (b) in Grifitths) asks to find <x^2> of the ground state of hydrogen atom. It asks to do so without new integration. Supposedly, there is some kind of symmetry and one can use the results from part (a) of the problem. Part (a) is finding <r> and <r^2> for...
  38. M

    How does look resistance when coming from atom to atom

    how does look resistance when coming from atom to atom? I mean what is making that resistance, something with space between them or atomic forces?
  39. T

    Work required to disassemble a helium atom

    Homework Statement A helium atom has a rest mass of He = 4.002603u. When disassembled into its constituent particles (2 protons, 2 neutrons, 2 electrons), the well-separated individual particles have the following masses: p = 1.007276u, n= 1.008665u, e = 0.000549u. How much work is required...
  40. B

    Ionization temperature of an atom

    Hi, How do we calculate the temperature required to ionize an atom, say, helium. Also how can we find the number of atoms ionized or unionized at a given temperature? Boltzmann
  41. T

    Finding the Quantum States for a Nitrogen Atom

    Homework Statement how many possible quantum states for a nitrogen atom with electronic configuration of 1s22s22p3 Homework Equations ? The Attempt at a Solution So, the answer for this question is 20, but I can't for the life of me find out how. The book we're given is...
  42. sunrah

    Recursion relation in the hydrogen atom

    Homework Statement Given the following recursion formula: b_{j} = 2 \frac{kj - a}{j(j+1)-l(l+1)} \cdot b_{j-1} (where a, k and l are constants) how can b_{j = l} \neq 0 if b_{j - 1} = 0. Homework Equations The Attempt at a Solution This is a part question and I really can't see why. if...
  43. C

    Most accurate way to visualise an atom.

    Good morning. I am wondering what is the most accurate way to visualise an atom. In class the teacher draws spheres orbiting spheres, but, according to quantum mechanics, that is far from the truth. How do physicists visualise atoms or particles? Thank you.
  44. S

    Webpage title: Understanding the Energy Levels of Electrons in Atoms

    Hello, why do the electrons with higher quantic number N have more energy than the electrons with lower N if they need less energy to be removed from the atom? Thank you!
  45. A

    Does a charge have spin outside an atom?

    Is spin of electron taken into account when people accelerate electron in LHC?
  46. W

    Possibly Stupid Question on Atom Smashing

    Suppose you theoretically have two betatrons each accelerating a particle near light speed in opposite directions. Suppose you collide both of these electrons together head on both at close to light speed. Since the collision is happening at speeds over the speed of light, does anything peculiar...
  47. N

    Stripping a neutron from an atom

    How do you strip a neutron from a particle? Thanks
  48. T

    Cesium Atom quantum mechanical description

    Hello guys, I need the quantum mechanical description of the Cesium atom/gas with its hyperfine states, and preferably with some density matrix. I don't really know where to start my search. I googled a lot, and looked for articles and books, but failed. Any help is highly appreciated...
  49. B

    Expression for recoil velocity of hydrogen atom during electron transition

    Hi all How does one calculate the recoil velocity of a hydrogen atom when the electron in it jumps from a higher orbit to a lower orbit (say from 3rd to 1st) ?
  50. 0

    What is of an atom and how common it is?

    Does a ground state of atom actually exist on our planet or every atom or molecule is just somehow excited because of all the energy flying around?
Back
Top