A neutron has charge 0 and a big mass.
They both have strong interactions.
It has a big mass.
Now we can see structure.
A helium nucleus is made of two protons and two neutrons.
A proton has charge +1 and a big mass.
A neutron has charge 0 and a big mass.
They both have strong interactions.
Davison E. Soper, Institute of Theoretical Science, University of Oregon, Eugene OR 97403 USA soper@bovine.uoregon.edu