I'm looking at the ionization energy of some elements and their work function. To my astonishment these energies are quite different (factor close to 2). How is that possible that if say a piece of copper has almost all its atoms in the fundamental state (room temperature ensures this I guess), it costs less energy to remove an electron from any atom of the solid than if the atom was alone. It must be because the other atoms are somehow "helping you" to remove the electron. Hmm, and if electrons are "shared" since it's a good conductor wouldn't atoms be constantly ionized and getting back to neutral charge after a very quick time? I'm somehow confused on what's going on. Also I'm interested in knowing the work function of hydrogen molecule to see how it differs from the ionization energy of the H atom, namely 13.6 eV. I don't find this information on the internet.