How many atoms of gold are in 1 gram of gold?

The important information or constant, in this case, to know is the Avogadro's constant. The constant is equal to 6.02214086 * 10^23 atoms/mol. Multiply this constant with the number of moles a gram of gold would contain.

= 1gram / (196.96g/mole) * 6.022 * 10^23 atoms/mol = 3.057*10^21 atoms.