<span>Mass of the copper penny m = 2.6 g
Atomic mass of copper = 63.55, Atomic number = 29,
So the number of neutrons = Atomic mass - Atomic number = 63 - 29 = 34
a. Neutron mass = 34 x (2.6 / 63.55) = 1.4 grams
Copper atoms per mole = 6.040 x 10^23 atoms/mol
moles of copper = 2.6 / 63.06 = 0.04123 mol
Total atoms in the copper = 6.040 x 10^23 atoms/mol x 0.04123 mol = 0.25 x 10^23 atoms
Number of electrons in the copper = 29 per atom
Mass of the electron = 9.085 x 10^-28 g
b. Electron mass = 0.25 x 10^23 x 29 x 9.085 x 10^-28 = 65.86 x 10^-5 g</span>
