In an atom, protons contribute more to its mass than electrons. While both particles are essential components of an atom, they have significantly different masses.
A proton has a mass of about 1.007 atomic mass units (amu), whereas an electron has a much smaller mass of approximately 0.0005 amu. In fact, the mass of an electron is so tiny compared to that of a proton that it is often considered negligible when determining the overall mass of an atom.
To put it simply, in the nucleus of an atom, you have protons (and neutrons) that account for the bulk of the mass, while the electrons orbiting outside the nucleus contribute very little to this total mass. Thus, in terms of mass contribution, protons are the substantial players in the atom.