Final answer:
The correct number of gold atoms in 3.55 moles is 2.137 × 10^24, which is not an option provided. Using Avogadro's number, the answer is determined by multiplying 3.55 moles by 6.022 × 10^23 atoms/mol.
Step-by-step explanation:
To calculate the number of gold atoms in 3.55 moles, we use Avogadro's number, which is 6.022 × 10^23 atoms/mol. One mole of any substance contains Avogadro's number of atoms.
So, the number of atoms in 3.55 moles is:
3.55 moles × 6.022 × 10^23 atoms/mol = 2.137 × 10^24 atoms
None of the options given (a) 6.022 × 10^23, (b) 1.805 × 10^23, (c) 2.689 × 10^23, (d) 9.871 × 10^23 exactly match the calculated number of gold atoms. However, the closest option to the calculated value would theoretically be (d) 9.871 × 10^23 if we round down the number of moles to 3 instead of 3.55.