How many moles of gold atoms are in 2.8 x 10 21 atoms of gold?

Therefore, 1 mole of gold weighs 196.9665 grams. So, in 2.8 grams of gold we would have:

(2.8 gram) (1 mole/196.9665 gram) = 0.0142 mole.

From Avogadro's number, we know that there are approximately 6.02 x 1023 atoms/mole.