Answers are grounded in this paper and cite their sources.
The edge spectrum is a sensitive probe of local chemistry. Edge spectra of potassium in various chemical environments were measured, and each environment gives a unique edge spectrum. Hydrated potassium has a unique spectrum that is insensitive to counterions. Comparison of the spectra shows that the chemical state of potassium in cells differs appreciably from that in aqueous solutions.
No takes yet. Share an insight, caveat, or question.
Huang et al. (1979) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: