The component of an atom that contributes least to its mass is the
Answer Details
The component of an atom that contributes least to its mass is the electron. The electron is a negatively charged subatomic particle that orbits the nucleus of an atom. It has a much smaller mass compared to the proton and neutron, which are found in the nucleus. Therefore, even though electrons are present in large numbers in an atom, their individual mass is so small that they contribute the least to the overall mass of the atom.