Electron's emission in Sn atom

[pollo93]

Good morning everybody, here's a problem about excitations energy of the core level of a Sn atom.
It says to construct the scheme of the core levels of Sn indicating the excitations energies. Now the K edge (the problem doesn't say we are necessarily talking about X-rays, but I think we are because of this notation) is at λ=0.425 A and the first two lines are Kα=0.517 A and Kβ=0.437 A. (A is for "angstrom": 10^-10 m)

Now shouldn't the excitations energies be just hc/λ ? Probably I actually didn't understand what Kα and Kβ are. I think they are the wavelengths of the emissed photoelectrons due to X-ray, but I'm probably wrong.

Who can help me? Thanks.

 

[Asim Riaz]

The excitation energies of a core level are typically described in terms of the binding energy, which is the energy required to remove an electron from the core level. The Kα and Kβ lines correspond to the wavelengths of the X-ray photons that are emitted when an electron is ejected from the core level. The excitation energy for a given core level is equal to the difference between the binding energy of that level and the binding energy of the next lower level. For example, in the case of a Sn atom, the binding energy of the K-shell is 54.8 eV and the binding energy of the L-shell is 19.2 eV. Therefore, the excitation energy of the K-shell would be the difference between these two values, which is 35.6 eV. This corresponds to a wavelength of 0.425 Å. The Kα and Kβ lines correspond to the emission of X-ray photons when electrons are ejected from the K-shell and the L-shell, respectively. The energy of these photons (i.e. the excitation energies) can be calculated by subtracting the respective binding energies from the K-shell binding energy:Kα: 54.8 eV - 46.3 eV = 8.5 eV (wavelength = 0.517 Å)Kβ: 54.8 eV - 32.2 eV = 22.6 eV (wavelength = 0.437 Å)Therefore, the scheme of the core levels of Sn indicating the excitation energies would look like this:K-Shell: 54.8 eV (λ = 0.425 Å)Kα: 8.5 eV (λ = 0.517 Å)Kβ: 22.6 eV (λ = 0.437 Å)L-Shell: 19.2 eV