(from
https://en.wikipedia.org/wiki/Atmosphere_of_the_Moon)
"The average daytime abundances of the elements known to be present in the lunar atmosphere, in atoms per cubic centimeter, are as follows:
Argon: 20,000–100,000
Helium: 5,000–30,000
Neon: up to 20,000
Sodium: 70
Potassium: 17
Hydrogen: fewer than 17
This yields approximately 80,000 total atoms per cubic centimeter, marginally higher than the quantity posited to exist in the atmosphere of Mercury.
While this greatly exceeds the density of the solar wind, which is usually on the order of just a few protons per cubic centimeter,
it is virtually a vacuum in comparison with the atmosphere of the Earth.
The Moon may also have a tenuous "atmosphere" of electrostatically-levitated dust."
----------------------------------------------------------------
Do metals sublimate?
Yes, they do, which is more significant in vacuum:
"The sublimation rate will depend on temperature and energy of sublimation, which is different for different metals.
Also in normal conditions you will have some kind of equilibrium - some of the particles that leave the surface will
condensate back. But in vacuum techniques you need to take this to account - there are metals with low sublimation
energy - such as Zinc, Magnesium, Cadmium e.t.c."