: 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

Examples of neutron in a Sentence

Recent Examples on the Web
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Lightbulb was also accompanied by a kilonova, a bright surge of radiation involving oodles of neutrons—the very kind that could kick-start the r-process and forge all those heavy elements. — Robin George Andrews, Scientific American, 20 Oct. 2026 Back in orbit, NASA's MEGANE instrument will measure Phobos' elemental composition through gamma-ray and neutron spectroscopy that can scan tens of centimeters beneath the moon's surface for signs of volatile elements. — Josh Dinner, Space.com, 18 Oct. 2026 The discovery provides a detailed view into how the dinosaur’s body responded to injury before its death and demonstrates how neutron imaging can reveal soft tissues that are rarely preserved in fossils. — Muskan Bhatia, Interesting Engineering, 16 Oct. 2026 Starting in 1960 at McMurdo, a neutron monitor measured low-energy cosmic rays – charged particles from outside the solar system. — Daniella McCahey, The Conversation, 12 Oct. 2026 See All Example Sentences for neutron

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

Cite this Entry

“Neutron.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/neutron. Accessed 25 Oct. 2026.

Kids Definition

: 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

: 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

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