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Name: Greg H.
Status: student
Age: 15
Location: N/A
Country: N/A
Date: 2001-2002

Why do neutrons stay in the nucleus of an atom? We just covered that in our science class and I was wondering since they have a negligible charge and I cannot see why they are there. If neutrons can go in a nucleus like that, what is there to stop them from forming a complete atom of their own? made just from neutrons?


It is believed that the nucleus of an atom is not held together by electric force. In fact, it must be a force much stronger than the electric force. If it were not, the protons in a nucleus would push each other away. This force has been labelled the Strong Force. Protons, neutrons, and other particles made of quarks feel this force. It is always attractive. The best-working model for it has protons and neutrons interacting with each other through the exchange of particles, usually particles called pions. This very strong, attractive force holds protons and neutrons just as well. It has nothing to do with electric charge.

Electrons do not feel the Strong Force. The strongest force electrons respond to the electric force. This is why a neutron cannot hold an electron in orbit. A neutron, having no electric charge, does not use the electric force.

I expect you to wonder why these things are so. Nobody knows why they have to be. We have theories about how these forces work, and about what allows particles to feel them. Science can explore how the universe works, but science cannot discover why the universe is designed as it is.

Dr. Ken Mellendorf
Illinois Central College

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