The mass of each proton and neutron is equal to
- Mass of proton and neutron is equal to
- The mass of each proton and neutron is approximately equal to
- 3 the mass of each proton and each neutron is approximately equal to
- The mass of proton and neutron is approximately equal to
- The mass of proton and neutron is nearly equal to
- Mass of neutron
- Neutron number
- Chemistry atomic mass number