Neutron: Difference between revisions
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imported>Howard C. Berkowitz (New page: {{subpages}} {{TOC-right}} A '''neutron''' is an elementary particle that normally is part of the nucleus of a chemical element. When not bound to a neutron, it can have import...) |
imported>Paul Wormer (Added mass) |
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| title = Ionizing Radiation | | title = Ionizing Radiation | ||
| url = http://www.who.int/ionizing_radiation/about/what_is_ir/en/index.html}}</ref> effects. | | url = http://www.who.int/ionizing_radiation/about/what_is_ir/en/index.html}}</ref> effects. | ||
The mass ''m''<sub>n</sub> of a neutron<ref> Value retrieved from [http://physics.nist.gov/cgi-bin/cuu/Value?mn NIST] on October 1, 2008</ref> is close to, but not equal to, the mass of a [[proton]]: | |||
:''m''<sub>n</sub> = 1.674 927 211 × 10<sup>−27</sup> kg . | |||
==History== | ==History== | ||
The existence of the neutron was discovered, in 1932, by Sir [[James Chadwick]], who received the 1935 [[Nobel Prize]] in Physics for his work. A repeatable experimental demonstration of the existence of the neutron solved a number of then-outstanding problems in physics, although the applications and significance of neutrons were in their infancy.<ref name=PhysLabNeutron>{{citation | The existence of the neutron was discovered, in 1932, by Sir [[James Chadwick]], who received the 1935 [[Nobel Prize]] in Physics for his work. A repeatable experimental demonstration of the existence of the neutron solved a number of then-outstanding problems in physics, although the applications and significance of neutrons were in their infancy.<ref name=PhysLabNeutron>{{citation | ||
Revision as of 08:08, 1 October 2008
Template:TOC-right A neutron is an elementary particle that normally is part of the nucleus of a chemical element. When not bound to a neutron, it can have important physical, chemical, and biological[1] effects.
The mass mn of a neutron[2] is close to, but not equal to, the mass of a proton:
- mn = 1.674 927 211 × 10−27 kg .
History
The existence of the neutron was discovered, in 1932, by Sir James Chadwick, who received the 1935 Nobel Prize in Physics for his work. A repeatable experimental demonstration of the existence of the neutron solved a number of then-outstanding problems in physics, although the applications and significance of neutrons were in their infancy.[3]
Role in the nucleus
Health effects
From the biological standpoint, neutrons are indirectly ionizing. [1]
References
- ↑ 1.0 1.1 World Health Organization, Ionizing Radiation
- ↑ Value retrieved from NIST on October 1, 2008
- ↑ Colwell, Catharine H., Famous Experiments: The Discovery of the Neutron, PhysicsLab