neutron

[ noo-tron, nyoo- ]

noun

, Physics.

1. an elementary particle having no charge, mass slightly greater than that of a proton, and spin of ½: a constituent of the nuclei of all atoms except those of hydrogen. : n

neutron

/ ˈnjuːtrɒn /

noun

1. physics a neutral elementary particle with a rest mass of 1.674 92716 × 10 ^–27kilogram and spin 1 2 ; classified as a baryon. In the nucleus of an atom it is stable, but when free it decays

neutron

/ no̅o̅′trŏn′ /

1. An electrically neutral subatomic particle in the baryon family, having a mass of 1.674 × 10 ^-24 grams (1,838 times that of the electron and slightly greater than that of the proton). Neutrons are part of the nucleus of all atoms, except hydrogen, and have a mean lifetime of approximately 1.0×10 ³ seconds as free particles. They consist of a triplet of quarks, including two down quarks and one up quark, bound together by gluons. In radioactive atoms, excess neutrons are converted to protons by beta decay. Beams of neutrons from nuclear reactors are used to bombard the atoms of various elements to produce fission and other nuclear reactions and to determine the atomic arrangements in molecules.
2. See Table at subatomic particle

neutron

1. An elementary particle without an electrical charge ; one of the building blocks of the nucleus of the atom . A neutron has about the same mass as a proton .

Word History and Origins

Origin of neutron¹

First recorded in 1920–25; neutr(o)- + -on ¹

Word History and Origins

Origin of neutron¹

C20: from neutral , on the model of electron

Example Sentences

The Crab Nebula features a neutron star at its center that has formed into a 12-mile-wide pulsar pinwheeling electromagnetic radiation across the cosmos.

From Science Daily

Finally elementary particles are protons, electrons, neutrons and all other particles that are smaller than an atom.

From Salon

When stars collapse, they can leave behind incredibly dense but relatively small and cold remnants called neutron stars.

From Science Daily

Quarks and gluons are the fundamental building blocks of protons and neutrons -- elementary particles that combined to forge the basic elements of the periodic table.

From Science Daily

Scientists have detected what they believe to be a neutron star spinning at an unprecedentedly slow rate -- slower than any of the more than 3,000 radio emitting neutron stars measured to date.

From Science Daily