What is the mass in grams of 100,000 gold atoms each weighing 197 amu

Answer 1

Google tells me that one amu (atomic mass unit) is 1.66 x 10^-24 grams. Since each of those gold atoms weighs 197 amu, it weighs 197(1.66 x 10^-24) grams, or 3.27 x 10^-22 g. 100,000 of them weigh 100,000(3.27 x 10^-22), or 3.27 x 10^-17 g.

Answer 2

100,000 atoms Au x 1 mol Au / 6.02x10²³ atoms = 1.66x10^-19 mols Au

1.66x10^-19 mols x 197 g / mol = 3.27x10^-17 g Au