Final answer:
To determine the number of atoms in a copper coin, divide the mass of the coin by the molar mass of copper and multiply by Avogadro's number.
Step-by-step explanation:
To determine the number of atoms in a copper coin, we need to use the mass of the coin and the molar mass of copper. The atomic mass of copper is 63.54 g/mol.
First, convert the mass of the coin from grams to moles by dividing by the molar mass. Then, multiply the number of moles by Avogadro's number (6.02 × 1023 atoms/mol) to get the number of atoms.
For example, if we have a 3.7 g copper coin:
Number of atoms = (3.7 g / 63.54 g/mol) × (6.02 × 1023 atoms/mol)
= 2.77 × 1022 atoms (rounded to two significant figures).