Questions: Which subatomic particle does not contribute significantly to the mass of an atom? Electron Neutron Proton

Solution Steps

The three main subatomic particles in an atom are electrons, neutrons, and protons.

• Protons and neutrons have similar masses, approximately \(1 \, \text{atomic mass unit (amu)}\).
• Electrons have a much smaller mass, approximately \(1/1836 \, \text{amu}\).

Since the mass of an electron is significantly smaller than that of protons and neutrons, it does not contribute significantly to the mass of an atom.

Final Answer