The two subatomic particles that have the same mass are the proton and the neutron. Both of these particles are found in the nucleus of an atom.
Protons and neutrons are very similar in mass, with each having a mass of approximately 1 atomic mass unit (amu). While protons are positively charged, neutrons are neutral, meaning they have no charge. Despite this difference in charge, their masses are nearly identical.
In contrast, electrons, which are much smaller and orbit the nucleus, have a significantly smaller mass compared to protons and neutrons. The mass of an electron is about 1/1836th the mass of a proton or neutron.
Understanding the masses of these subatomic particles is crucial in the study of atomic structure and chemistry, as it helps explain the behavior and properties of different elements.