# Successive work functions for solid-state metals

I was wondering if there are tables for successive work functions for (solid state) metals? All I can find are work functions to remove 1 electron from the surface of a metal into vacuum (and to keep it there). However, I guess it gets harder to remove electrons the more electrons already have been removed, right?

Maybe there's a way to relate the work function to the average degree of ionization of the material... do you know if that is possible at all? I've heard about the Thomas-Fermi approximation which relates the mean degree of ionization to the electron-temperature and electron-density but that seems to be rather inaccurate.

Finally, I'd like to know your opinion: Is it harder to ionize a metal gas or a metal solid? Although most work functions are a little bit smaller than the (1st) ionization-energies of the same material in gaseous state but I still think ionization of solids is harder. Do you agree?

• Thanks for your reply but I'm not talkin about ionization energies. These are always given for gaseous matter. That is not the same as work functions...I'm interested in ionization of solid (crystalline) metals. Aug 3 '16 at 15:30
• to quote your question, "I am wondering if there are tables for successive ionization energies for metals" (italics my own). My apologies about the metals part, but I think you are talking about ionization energies. Aug 3 '16 at 15:32
• Please note that questions which ask for opinions are off topic. I suggest that you revise your final paragraph. Otherwise the question seems ok to me. Aug 3 '16 at 17:43
• This Qn has also been posted to Chemistry SE : chemistry.stackexchange.com/questions/55939 Aug 3 '16 at 17:47

If the metal object does acquire a significant charge $Q$ due to loss (or gain) of electrons, the effect on the energy needed to remove further electrons can be calculated from the capacitance $C$ of the object. This can be measured experimentally or (for regular shapes) calculated. A +ve charge $Q$ raises the electric potential of the metal object by $V=\frac{Q}{C}$, which increases the work function by $V$ electron-volts.
If the metal object is maintained at a constant potential $V$ - eg by connection to ground or to a voltage supply - any charge on the metal object is dealt with the same way.