## College Physics (4th Edition)

The gold would have a net charge of $+386~C$
One atom of gold has 79 protons, 118 neutrons, and 79 electrons. The mass of one atom of gold is $197~u$. Therefore, one mole of gold atoms has a mass of 197 grams. We can find the number of gold atoms in 1 gram: $(\frac{1~g}{197~g})~(6.022\times 10^{23}) = 3.057\times 10^{21}$ We can find the number of electrons which are removed: $(0.01)(3.057\times 10^{21})(79) = 2.415\times 10^{21}$ We can find the negative charge that was removed: $(-1.6\times 10^{-19}~C)(2.415\times 10^{21}) = -386~C$ Since a charge of $-386~C$ was removed, the gold would have a net charge of $+386~C$.