Answer:
Step-by-step explanation:
mas of proton = 1.673 x 10^-27 kg
mass of neutron = 1.675 x 10^-27 kg
mass of electron = 9.1 x 10^-31 kg
(a) the mass of proton and the mass of neutron is not exactly same.
(b) mass of proton = 1838.46 x mass of electron
mass of neutron = 1840.65 x mass of electron
(c) As proton and neutrons are more massive than the electrons, so the protons and the neutrons has the greatest contribution of mass of an atom.
(d) The greatest contribution to the chemical properties of an atom is due to the electrons.