We argue that for granular metals a sizable fraction of the grains bec
omes charged because the energy fluctuation of the highest-occupied le
vel of each grain, as predicted by random matrix theory, is larger tha
n the charging energy. We have computed the ground state density of st
ates and the degree of ionization of granular metals. The density of s
tates shows a Coulomb gap around the Fermi energy, produced by the lon
g-range part of the Coulomb interactions, which should dominate transp
ort properties at low temperatures.