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Name: Sara H.
Status: student
Age: 16
Location: N/A
Country: N/A
Date: Thursday, November 28, 2002

Do the neutrons in an atom's nucleus have any purpose besides deciding what isotopes the atom has?

Neutrons do not need a purpose. Just like electrons, protons, atoms, and so on. NEUTRONS EXIST, and they have certain properties. These are experimental observations, and as such do not need a "purpose". THEY ARE.

Vince Calder


Neutrons are important to the nucleus. Most importantly, neutrons hold the nucleus together. All protons have an electric charge. All have the same charge. All protons repel each other with the electric force. But when they are close together, this does not matter much. Protons AND neutrons have a very short range force called the strong force. When right next to each other, this strong force is much more powerful than the electric force. If the protons would sit still in a nucleus, this would be enough. However, this only happens at VERY cold temperatures, near what is called "absolute zero": 273 degrees below zero on the Celsius scale. At common temperatures, protons are jumping all over they place. They need extra holding force to stay in the nucleus. This is where neutrons come in.

Neutrons, like protons, have this strong force that attracts neighboring nucleons. Unlike protons, neutrons do not have electric charge. They are only attracted to each other and to protons. Their strong force helps hold the nucleus together more tightly than the protons alone can accomplish. All protons work together to push on each other. As a nucleus gets larger, it gets more electric force pushing out the protons. A larger nucleus needs more neutrons. Look at the elements. The lighter elements are about half proton and half neutron. The heaviest elements have many more neutrons than protons.

Dr. Ken Mellendorf
Physics Instructor
Illinois Central College

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