Question

Which parts of an atom contribute most to its mass?

Answer 1

the nucleus

Step-by-step explanation:

The protons and neutrons in the center of the atom are about 2,000 times heavier than the electrons orbiting around it. Because the electrons are so light by comparison, they represent only a tiny fraction of a percent of the atom's total weight.

Answer 2

nucleus

Step-by-step explanation:

the nucleus is made of protons and neutrons that make up the mass of the atoms, electrons have negligible masses