neutron

noun

neu·​tron ˈnü-ˌträn How to pronounce neutron (audio)
ˈnyü-
: an uncharged elementary particle that has a mass nearly equal to that of the proton and is present in all known atomic nuclei except the hydrogen nucleus
neutronic adjective

Examples of neutron in a Sentence

Recent Examples on the Web The most common forms occur when an unstable nucleus spits out an alpha particle, consisting of two neutrons and two protons, a beta particle consisting of an energetic positron or electron, or a gamma ray, consisting of a high energy photon. The Physics Arxiv Blog, Discover Magazine, 27 Feb. 2024 Isotopes are different forms of the same element that have the same number of protons but different numbers of neutrons; the most common actinium isotope is 227, with two more neutrons than 225. Sarah Scoles, Scientific American, 13 Feb. 2024 That number is the atomic weight—the total number of protons and neutrons in the nucleus of the atom. Rhett Allain, WIRED, 23 Feb. 2024 When the universe began to cool down, the protons and neutrons began to combine into ionized atoms of hydrogen. Laura Baisas, Popular Science, 18 Jan. 2024 Such measurements are currently underway for neutrons and for mercury nuclei, and many more are planned. Luke Caldwell, Scientific American, 16 Jan. 2024 In a popular variant called cold dark matter, these leftover particles would be heavy and slow compared with protons, neutrons and the other, more familiar denizens of the quantum atomic world. Dennis Overbye, New York Times, 5 Jan. 2024 Technically, a cosmic ray is just an atomic nucleus made up of a proton or a cluster of protons and neutrons. Jennifer Ouellette, Ars Technica, 23 Nov. 2023 In his laboratory at the Kaiser-Wilhelm Institut, Hahn had found that when uranium was bombarded with slow-moving neutrons, the result was smaller, lighter elements. Ashraya Gupta, Scientific American, 14 Sep. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'neutron.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

probably from neutral

First Known Use

1921, in the meaning defined above

Time Traveler
The first known use of neutron was in 1921

Dictionary Entries Near neutron

Cite this Entry

“Neutron.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/neutron. Accessed 29 Mar. 2024.

Kids Definition

neutron

noun
neu·​tron ˈn(y)ü-ˌträn How to pronounce neutron (audio)
: an uncharged atomic particle that has a mass nearly equal to that of the proton and is present in all known atomic nuclei except the hydrogen nucleus

Medical Definition

neutron

noun
neu·​tron ˈn(y)ü-ˌträn How to pronounce neutron (audio)
: an uncharged elementary particle that has a mass nearly equal to that of the proton and is present in all known atomic nuclei except the hydrogen nucleus

More from Merriam-Webster on neutron

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