Label	Orbital	eV [literature reference]
	K	1s	4038.5 [2]
	L I	2s	438.4 [3]
	L II	2p1/2	349.7 [3]
	L III	2p3/2	346.2 [3]
	M I	3s	44.3 [3]
	M II	3p1/2	25.4 [3]
	M III	3p3/2	25.4 [3]

Notes

All values of electron binding energies are given in eV. The binding energies are quoted relative to the vacuum level for rare gases and H₂, N₂, O₂, F₂, and Cl₂ molecules; relative to the Fermi level for metals; and relative to the top of the valence band for semiconductors.

I am grateful to Gwyn Williams (Jefferson Laboratory, Virginia, USA) who provided the electron binding energy data. The data are adapted from references 1-3. They are tabulated elsewhere on the WWW (reference 4) and in paper form (reference 5).