Question

Essentially all of the mass of an atom is due to the ______.(A) electrons.(B) neutrons.(C) nucleons.(D) protons.

Answer 1

Answer:

Atom is made up of NUCLEUS and electrons revolving around nucleus.

Nucleus itself contains protons and neutrons. Protons and neutrons are approximately 1680 times heavier than the electrons. So the major contribution to the mass of an atom comes from the nucleus.