Potassium

K 2p3/2 binding energies.
K 2p3/2-1/2 splitting is 2.77 to 2.8 eV.

Notes: Often will see K 2p peaks in high resolution C 1s spectra. Be careful not to confuse these peaks with contributions from C 1s fluorocarbon peaks or pi -> pi* shake-up structure.

For quantification in survey scans it is ofter easier to use the K 2s peak (~380 eV) as the K 2p peak may not be fully separated from the C 1s peak at lower resolutions.