Ooo I just learned this :)
Mass table:
Electron: 0.000548
Positron: 0.00055
Neutrino: < 1.0
Mesons: 0.125
Proton: 1.007582
Neutron: 1.00897
Alpha Particle: 4.002764
Your answer: The mass that’s most close to proton’s mass “1.007582” is neutron’s mass “1.00897”.
Please mark as BRAINLIEST:)
And have a nice day buddy :)