## Chemistry and Chemical Reactivity (9th Edition)

a) The foil's thickness is too large relative to the radius of a silver atom to make it impossible. b) There can't be a fractional number of atoms, but this number is in scientific notation, so it's most likely a very large integer, so it's possible. c) The mass of the coin is too large relative to the mass of a single gold atom to make it impossible. d) Since this number is less than the inverse of the Avogadro's number ($1.66\times10^{-24}$), it means that there would be a fractional number of atoms, which is impossible.