Question

The atomic mass of an atom equals the sum of the masses of the _____.

protons and electrons
electrons and neutrons
protons and neutrons
protons only

Answer 1

protons only

neutral has no difference on the mass

but to be safe i don't know about electrons

positive protons is one tho

Answer 2

protons and neutrons

Step-by-step explanation:

The masses of the protons and neutrons in an atom contribute to nearly all the mass of the atom. The electrons have negligible mass so it is ignored. The mass of a proton is 1.6726219 × 10⁻²⁷ kilograms. The mass of a neutron is 1.660540 x 10⁻²⁷ kg. The mass of an electron is 9.10938356 × 10⁻³¹ kg. The difference in the masses can be clearly seen.