neutron

[ noo-tron, nyoo- ]

/ ˈnu trɒn, ˈnyu- /

noun Physics.

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. Symbol: n

Nearby words

neutretto, neutrino, neutrino astronomy, neutro-, neutrois, neutron, neutron bomb, neutron gun, neutron moderator, neutron number, neutron poison

Origin of neutron

First recorded in 1920–25; neutr(o)- + -on¹

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for neutron

Deuterium is an isotope of hydrogen containing a proton and neutron in its nucleus, while normal hydrogen has only a proton.
Are Comets the Origin of Earth’s Oceans?|Matthew R. Francis|December 14, 2014|DAILY BEAST
You have the atom, which has the neutron, the electron, the proton.
‘Crazy’ Harlem Pastor Hates on Obama and Gays|Olivia Nuzzi|September 28, 2014|DAILY BEAST
While every neutron star has an intense magnetic field, the ones known as magnetars are exceptional.
The Weirdest Object in the Universe|Matthew R. Francis|May 18, 2014|DAILY BEAST
For that reason, such objects are called pulsars, and they have provided our best data about neutron stars.
The Weirdest Object in the Universe|Matthew R. Francis|May 18, 2014|DAILY BEAST

The pulses are from a beam of light produced by the intense magnetic field, which sweeps across Earth as the neutron star rotates.
The Weirdest Object in the Universe|Matthew R. Francis|May 18, 2014|DAILY BEAST
They spotted the dome of the station, and a neutron ray lashed out at it.
The Ultimate Weapon|John Wood Campbell
As he watched, the air around it fairly sizzled blue with the rays of neutron disruption blasters, and then it blew apart.
Time Crime|H. Beam Piper
In 1932, during the early search for more efficient ways to bombard nuclei, James Chadwick discovered the neutron.
A Brief History of Element Discovery, Synthesis, and Analysis|Glen W. Watson
It is, in fact, these properties of the neutron which have made possible the utilization of atomic energy.
A Brief History of Element Discovery, Synthesis, and Analysis|Glen W. Watson
Sokolski checked his neutron tab and his gamma reader and they stepped over the threshold.
The Small World of M-75|Ed M. Clinton, Jr.

British Dictionary definitions for neutron

neutron

/ (ˈnjuːtrɒn) /

noun

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

Word Origin for neutron

C20: from neutral, on the model of electron

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for neutron

neutron

[ nōō′trŏn′ ]

n.

An electrically neutral subatomic particle in the baryon family, having a mass 1,839 times that of the electron, stable when bound in an atomic nucleus, and having a mean lifetime of approximately 1.0X103 seconds as a free particle. It and the proton form nearly the entire mass of atomic nuclei.

Science definitions for neutron

neutron

[ nōō′trŏn′ ]

An electrically neutral subatomic particle in the baryon family, having a mass of 1.674 X 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 1.0X103 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. See Table at subatomic particle.

Culture definitions for neutron

neutron

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.