Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Purpose of Neutrons 
Name: Sara H.
Status: student
Age: 16
Location: N/A
Country: N/A
Date: Thursday, November 28, 2002
Question:
Do the neutrons in an atom's nucleus have any purpose besides deciding what isotopes the atom has?

Replies:
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

Sara,

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


Click here to return to the Physics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory