Question

which particles have approximately the same size and mass as each other?
electrons and protons
none - they are all very different in size and mass
protons and neutrons
neutrons and electrons

Explanation:

In an atom, protons and neutrons are found in the nucleus. They have approximately the same mass (proton mass is about 1.6726219×10⁻²⁷ kg and neutron mass is about 1.674927471×10⁻²⁷ kg) and are of similar size compared to electrons which are much smaller and lighter.

Answer:

protons and neutrons