Carbon energy transition levels

[brocq_18]

How do I find the energy difference between 1s and 2p, in a carbon atom? I'm right in assuming this is a constant value, and yet I cannot find the answer anywhere..?

Thanks

 

[SpectraCat]

How do I find the energy difference between 1s and 2p, in a carbon atom? I'm right in assuming this is a constant value, and yet I cannot find the answer anywhere..?

Thanks

Actually, it's far from constant .. it depends on the chemical environment of the carbon atom. The 2p orbitals are valence orbitals, and mix with orbitals on other elements to form chemical bonds. You can probably find the value for the separation in a free atom, but that is probably the only place where the distinction makes sense. Even in allotropes of elemental carbon (i.e. graphite, diamond, fullerenes), the bonding between the C-atoms are different, so the energy gap is going to be different.

Anyway, the experimental technique that is most directly sensitive to the quantity you are interested in is probably Auger-electron spectroscopy (http://en.wikipedia.org/wiki/Auger_electron_spectroscopy). I would recommend searching online using Auger as a keyword. Another technique that can reveal such differences is photoelectron spectroscopy (PES). However, in that case you would need to compare separate values for the core (1s) and valence (2p) electrons, and as I said, those will be highly dependent on the chemical environment. I would suggest starting with diamond or graphite when looking for values. Also, note that the core levels will be measured by Xray photoelectron spectroscopy (XPS), while the valence levels are more in the vacuum ultraviolet (VUV), so you'll probably need to look in two different places for the numbers you need.

 

[brocq_18]

Thanks for your response SpectraCat. How would I proceed if this is the only information I am given in a question; Look up the constants delta and beta at carbon 2p - 1s transition energy for tungsten and carbon. Answer the following questions, which all refer to this energy...

I believe I know how to find the answers to the qustions, but I do not understand how to find this energy. Especially as I now know it is not a constant..