## College Physics (4th Edition)

The mass of one gold atom is $3.27\times 10^{-25}~kg$
A gold atom consists of 79 protons and 118 neutrons. The mass of one gold atom is $197~u$ We can convert this mass to units of $kg$: $m = 197~u\times \frac{1.66\times 10^{-27}~kg}{1~u} = 3.27\times 10^{-25}~kg$ The mass of one gold atom is $3.27\times 10^{-25}~kg$