the smallest component of an element having the chemical properties of the element, consisting of a nucleus containing combinations of neutrons and protons and one or more electrons bound to the nucleus by electrical attraction; the number of protons determines the identity of the element.
an atom with one of the electrons replaced by some other particle: muonic atom;kaonic atom.
Energy. this component as the source of nuclear energy.
a hypothetical particle of matter so minute as to admit of no division.
anything extremely small; a minute quantity.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
How to use atom in a sentence
The atoms vibrate less, and because such vibrations are simply heat, the alloy’s temperature drops.
Einstein used Brownian motion to deduce the existence of atoms, which bombard the microscopic particles.
It is really fascinating that atoms and quarks, following very different rules, can both form very similar complex objects.CERN: Physicists Report the Discovery of Unique New Particle | Harry Cliff | July 15, 2020 | Singularity Hub
Lenz noted that if most atoms pointed together, their tiny magnetic fields would fuse, and the material would act like a magnet overall.The Cartoon Picture of Magnets That Has Transformed Science | Charlie Wood | June 24, 2020 | Quanta Magazine
A negatively charged oxygen atom sits at the bottom of that “V,” explains Xia.Here’s one way to harvest water right out of the air | Sid Perkins | April 24, 2020 | Science News For Students
Check: “This atom smashing business is going to herald the final victory of the machine.”Mailer’s Letters Pack a Punch and a Surprising Degree of Sweetness | Ronald K. Fried | December 14, 2014 | THE DAILY BEAST
They found that there are roughly 1,900 hydrogen atoms for each deuterium atom in the water on Comet 67P.
Releasing a new issue was like dropping an atom bomb on the industry.It Was All a Dream: Drama, Bullshit, and the Rebirth of The Source Magazine | Alex Suskind | October 14, 2014 | THE DAILY BEAST
You have the atom, which has the neutron, the electron, the proton.
A face in a sea of faces, how could you know he hid among them like Oppenheimer, building a lab to split the atom.The Stacks: How Leonard Chess Helped Make Muddy Waters | Alex Belth | August 2, 2014 | THE DAILY BEAST
Standing in the wet shingle, Maynard regarded the speckled atom as it lay in the palm of his hand.Uncanny Tales | Various
Such an atom would by the rotation of the sphere accomplish no motion except, indeed, that it might turn round on its own centre.Outlines of the Earth's History | Nathaniel Southgate Shaler
She had a governess and she had a maid, but I must say she didn't seem an atom set up, and was just as nice when she met us girls.The Cromptons | Mary J. Holmes
The loss of one electron by an atom leaves a unit positive charge on the particle.The Elements of Qualitative Chemical Analysis, vol. 1, parts 1 and 2. | Julius Stieglitz
The smallest atom, when she chooses to make use of it, is obliged to obey her will.Buffon's Natural History. Volume IX (of 10) | Georges Louis Leclerc de Buffon
British Dictionary definitions for atom
the smallest quantity of an element that can take part in a chemical reaction
this entity as a source of nuclear energy: the power of the atom See also atomic structure
any entity regarded as the indivisible building block of a theory
the hypothetical indivisible particle of matter postulated by certain ancient philosophers as the fundamental constituent of matter: See also atomism
a very small amount or quantity; minute fragment: to smash something to atoms; there is not an atom of truth in his allegations
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
Scientific definitions for atom
The smallest unit of an element, consisting of at least one proton and (for all elements except hydrogen) one or more neutrons in a dense central nucleus, surrounded by one or more shells of electrons. In electrically neutral atoms, the number of protons equals the number of electrons. Atoms remain intact in chemical reactions except for the removal, transfer, or exchange of certain electrons. Compare compound. See also ion isotope orbital.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Cultural definitions for atom
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.