Neutron Definition in Chemistry

Composition, Meaning, and Charge

A 3D atom model

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The neutron is the particle in the atomic nucleus with a mass = 1 and charge = 0. Neutrons are found together with protons in the atomic nucleus. The number of neutrons in an atom determines its isotope.

Although a neutron has a net neutral electrical charge, it does consist of charged components which cancel each other out with respect to charge.

Neutron Facts

  • A neutron is a type of hadron. It consists of one up quark and two down quarks.
  • Although the mass of a proton and a neutron are comparable, especially compared with the much lighter electron, a neutron is slightly more massive than a proton. A neutron has a mass of 1.67492729 x 10-27 kg.
  • A neutron is considered a type of fermion because it has a spin = 1/2.
  • Although it's possible to eject neutrons from the nucleus, the free particles don't last long before reacting with other atoms. On average, a neutron survives on its own about 15 minutes.
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Helmenstine, Anne Marie, Ph.D. "Neutron Definition in Chemistry." ThoughtCo, Apr. 5, 2023, Helmenstine, Anne Marie, Ph.D. (2023, April 5). Neutron Definition in Chemistry. Retrieved from Helmenstine, Anne Marie, Ph.D. "Neutron Definition in Chemistry." ThoughtCo. (accessed June 10, 2023).