Question: how many copper atoms are in the penny?
Answer: Since a mole of atoms contains 6.0221 x 1023 atoms, there are 2.2452 x 1022 zinc atoms and 5.9230 x 1020 copper atoms in a penny, for a total of 2.3044 x 1022 atoms in a penny. Public Domain Image, source: NASA/JPL-Caltech.