Question

2 an atom’s mass is measured in atomic mass units (amu). try adding more protons, neutrons, and electrons to the model. which two subatomic particles increase the mass number of an atom?
protons

neutrons

electrons

Explanation:

The mass number of an atom is the sum of protons and neutrons in its nucleus. Electrons have negligible mass compared to protons and neutrons, so they do not contribute to the mass number. Protons and neutrons each have a mass of approximately 1 atomic mass unit (amu), so adding more protons or neutrons increases the mass number.

Answer:

Protons, Neutrons