What is Emission: Definition and 566 Discussions

The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an atom or molecule making a transition from a high energy state to a lower energy state. The photon energy of the emitted photon is equal to the energy difference between the two states. There are many possible electron transitions for each atom, and each transition has a specific energy difference. This collection of different transitions, leading to different radiated wavelengths, make up an emission spectrum. Each element's emission spectrum is unique. Therefore, spectroscopy can be used to identify elements in matter of unknown composition. Similarly, the emission spectra of molecules can be used in chemical analysis of substances.

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

    Why Does an Excited Electron Decay to the Ground State?

    Can someone please explain why an excited electron in an atom decays to the ground state, if energy eigenstates are stationary states.
  2. J

    Calculating Quanta Emission Rate for a Radio Station at 103.7 MHz and 200 KW

    A radio station operates at a frequency of 103.7 MHz with a power output of 200 KW. Determine the rate of emission of quanta from the station. Well I know the frequency and the power. I know the number of photons a second = (Power * Area) / ( Plancks Constant * Speed of Light ) / Lambda...
  3. J

    Joe's Uranium Problem: Alpha Particle Emission & Final Nucleus Mass

    Here I have a problem: A 232/92 Uranium nucleus emits an alpha particle with kinetic energy=5.32MeV. What is the final nucleus and what is the approximate mass(in units) of the final atom. I can write the equation for the reaction, this will give 4/2 He and 228/90 Th. If the alpha particle...
  4. V

    Photon Emission Rate and Optics Questions

    I'm really lost on these 3 questions. My physics teacher decided she was sick of thermodynamics and gave us this packet over material we haven't covered yet, but she expects us to get it without any problem. I'm really stuck on these: 1. Assume that sodium produces monochromatic light with a...
  5. W

    Optical Emission - due to Acceleration or Oscillation

    Three Interconnected Questions: 1. When an atom is excited by a visible photon (KE=1 eV), does the probability (radial) density increase for the valence electrons or not? 2. If the probability density has increased outward, then what normally causes the excited state to begin the process...
  6. C

    Thermionic Emission: What Causes Electrons to be Emitted?

    Thermionic Emission... Why exactly does thermionic emission happen? ie - Why does heating a metal cause electrons to be emitted? I know that it must be that the heat is giving the electrons enough energy to escape from their atoms but in what form is this? ie - I know that electrons can be...
  7. Chi Meson

    Emission lines of flourescent bulbs

    Hey does anyone know of a site where I can get the wavelengths of the strong emission lines of standard compact flourescent bulbs? It's very similar to mercury emission lines, but not the same exactly.
  8. T

    Hi, quick problem regarding emission of gamma ray.

    A Fe (57) atom is in an excited state 14.4 keV above the ground state. The nucleus decays to the ground state with the emission of a gamm ray. What's the recoil speed of the nucleus? I'm not sure how to set this up. I thought a photon would have no mass, therefor no momentum. If so I...
  9. V

    Exploring Earth's History through Acoustic Emission: A Scientist's Perspective

    Could you please give me some pages or materials about this AE ? Where can i find out some nice tutorials ? Thanks
  10. K

    Is it the Atom or the Electron? Understanding the Photon Emission Process

    when an excited electron emits a photon what happens to the EM field of the electron
  11. T

    Velocity of Light Emission: Lightspeed or More?

    Is the top speed of light emitted by something the velocity of the light emitter + lightspeed or just lightspeed?
  12. M

    Questioning EM Waves, Synchrotron Emission & Blackbody Radiation

    I'm reading an astronomy textbook, and I'm not sure about some things. The textbook says the EM waves are caused by accelerating charges. I don't understand how this is. I'm not sure, but my memory and intuition tells me that only charges moving in a sinuosidal (can never spell it) manner...
  13. S

    Is the direction of a photon's momentum uncertain when emitted from an atom?

    Classically, a pulse of light emitted by an atom would be viewed as an electromagnetic wave radiating spherically symmetrically out from the atom. Quantum mechanically speaking, if say a hydrogen atom emits a single photon, does the photon's wavefunction spread out spherically, us having no idea...
  14. S

    Need image of absorption and emission spectra for sodium

    Hi, I need images of absorption and emission spectra for sodium to be used in a physics student book. Thanks in advance Stanley
  15. P

    Physics.nature of emission of radiation from atoms

    Physics...nature of emission of radiation from atoms Hi everyone i am a Yr 11 student studying physics and i recently got an assignment that consists of a question that i cannot find thouroughly on the internet...hopeing people of this forum can help me... my question is...
  16. enigma

    Radioactivity is an emission of gamma particles

    This may be a dumb question: What is it about radioactivity that caused them to name it "radioactive"? All I was taught was that radioactivity is an emission of gamma particles, beta particles, or alpha particles. I don't remember anything about radio wavelength photons.
Back
Top