Chlorine

Cl 2p3/2 binding energies[1].  a) From standards run at Surface Science Western.

Note: Cl 2p3/2 - 2p1/2 separation is 1.60 eV

Cl 2s: 271 eV
Cl 3s: 17 eV
Cl 3p: 6 eV

On a Cl+ ion bombarded silicon wafer surface, Cl 2p3/2 for Cl-Si is 199.4 eV and for Cl-O-Si is 200.8 eV [2].

References:
[1] C.D. Wagner, A.V. Naumkin, A. Kraut-Vass, J.W. Allison, C.J. Powell, J.R.Jr. Rumble, NIST
Standard Reference Database 20, Version 3.4 (web version) (http:/srdata.nist.gov/xps/) 2003.
[2] I. Bello, W.H. Chang, W.M. Lau, J. Appl. Phys. 75 (1994) 3092.