# Tag Info

## New answers tagged spectroscopy

2

What emission lines? Unless you are looking at the chromosphere or corona the Sun does not have emission lines. Of course you can estimate photospheric abundances from a photospheric absorption line spectrum. That is how the solar abundances are estimated for most elements. However, you need a good spectrum to perform a detailed analysis. It should have ...

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Using the basic equipment at your disposal, this will not be possible. A naive approach would be to take the measured line amplitudes, divide by the line-integrated absorption coefficients at the wavelength of each line for some nominal set of parameters characteristic of the solar atmosphere, then divide out the emission coefficients and compare the ...

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This is going to take a bit, so be prepared. Also, some of what I say will not be exactly correct, in order to get the larger point across, but bear with me. First, the Rutherford model really did not speak to the question of emission lines. It simply noted that, on the basis of Rutherford's scattering experiments, all of the protons in an atom had to be ...

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Hydrogen is a stable atom and its spectrum is discontinuous and was fitted mathematically by the Rydberg series. Classical electromagnetic theory predicts that the electron, due to its continuous acceleration on the orbit, would emit photons continuously and would drop to a lower energy until it fell on the proton and neutralized it. To explain the ...

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Distinct spectral lines (rather than an infinite range of energies and hence white light) are a result of only specific transitions being allowed, which implies a set of distinct and unvarying energy levels. Classical models of the atom before quantum mechanics couldn't explain why there should only be certain electron energy levels.

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In this particular example the photoluminescence is of quantum wells. The reason for the asymmetry is because the density of states is not symmetric. At the low energy side the density of states has a excition Lorentzian line shape to the absorptivity. At higher energies the density of states becomes step like. The photoluminescence intensity,  I(E) ...

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The probability of a photon of energy $E$ — or corresponding wavelength $\lambda = h c / E$ — being absorbed by an atom and bringing an electron from level $i$ to level $j$ is given by the cross section $\phi_{ij}(\lambda)$, which is a sharply peaked function of wavelength (a so-called Lorentzian function). For instance, to bring a hydrogen atom ...

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An incoming photon of energy 2.5 eV hits an electron in the atom (with the lowest energy level) which is excited and moves up one enery level. In most cases, this won't happen. The incoming energy must match the transition that is being excited. It's possible for a 2.5 eV photon to excite a 2 eV transition, but only if there is some other particle ...

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