The mass of a proton is approximately equal to
(1) 1 atomic mass unit
(2) 12 atomic mass units
(3) the mass of one mole of carbon atoms
(4) the mass of 12 moles of carbon atoms

The correct answer is option 1. The mass of a proton is approximately equal to 1 atomic mass unit. They almost have the same mass with a neutron while the electron is about 2000 times lighter than the two. The three mentioned particles are the subatomic particles found in an atom.