Answer:
Step-by-step explanation:
molecular weight of gold = 197
converting 10.2 g into moles
no of moles = 10.2 / 197
= .0518 moles
one mole of any element contains 6.02 x 10²³ number of atoms
.0518 moles will contain 6.02 x .0518 x 10²³ atoms of gold
= .311 x 10²³ no of atoms of gold .
= 3.11 x 10²² no of atoms of gold