Definition of atom in English:



  • 1The basic unit of a chemical element.

    • ‘They have six atoms of carbon in each molecule and are therefore called hexoses.’
    • ‘By the end of the century J. I. Thomson would reveal that atoms could also be divided into parts.’
    • ‘The world of atoms and photons does not follow the rules of classical physics.’
    • ‘Water seems like the perfect energy source, packed, as it is, with two atoms of hydrogen per molecule.’
    • ‘Until now, molecules with fewer than 60 carbon atoms have only been made in the gaseous phase.’
    • ‘The electric field set up inside the tube excites atoms of mercury gas, making them emit ultraviolet light.’
    • ‘Ordinary gas is made from atoms that consist of electrons orbiting around nuclei.’
    • ‘Polychlorinated dibenzodioxin is 10 times more potent a toxin than hexachlorodibenzodioxin, even though the difference is just one chlorine atom.’
    • ‘Lam says that teleporting single atoms and molecules could be perfected within the next ten years.’
    • ‘Radioactive atoms decay into stable atoms by a simple mathematical process.’
    • ‘Its atoms have a nucleus of two protons and two neutrons, orbited by two electrons.’
    • ‘As can be seen, each silicon atom bonds together with four of its neighbors to form a rigid crystal structure.’
    • ‘Dr Lewis said the acrosome reaction involved the channelling of charged calcium atoms, or ions.’
    • ‘This is caused by the movement of an atom or group of atoms from one position to another.’
    • ‘Since all the variety we see around us is just a product of different arrangements of a few types of atom, nanotech has been hyped as a potentially limitless miracle technology.’
    • ‘These are electrically charged atoms of magnesium that form part of the gas surrounding a black hole.’
    • ‘Until now it has been impossible for scientists to detect every atom in the structure of protein molecules, which play a vital role in the body.’
    • ‘As early as 1991 Japanese researchers discovered that carbon atoms can form tiny tubes whose walls are just one atom thick.’
    • ‘It reminds me of cell division in an embryo or the arrangement of atoms in a molecule.’
    • ‘Bacteria that can break down chlorinated compounds have been known for years, but none that could remove the last chlorine atom to complete the detoxification.’
    • ‘Each radium atom is decaying into four more alpha-emitting radionuclides, creating in all 12,500 particles.’
    • ‘Everything is physical; the only things that exist consist of atoms in motion.’
    • ‘At the time, it was believed that electrons colliding with atoms always lost energy.’
    • ‘In simulations it is possible to calculate atom density, mass density, and electron density profiles.’
    • ‘Once removed from an atom, an electron may in turn ionize other atoms or molecules.’
    • ‘Recall also that one of the initial triumphs of quantum mechanics was to explain the stability of atoms.’
    • ‘If it were a little more curved it would collapse, imploding on itself in a cosmic crunch; a little less curved, and every star, planet, sun and galaxy would fly apart from each other and so would every atom of matter in each of them.’
    particle, molecule, bit, little bit, tiny bit, tiny piece, fragment, fraction, grain, granule, crumb, morsel, mite, mote, speck, spot, dot
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    1. 1.1 Atoms as a source of nuclear energy.
      ‘the power of the atom’
      • ‘One day soon, man is going to be able to harness incredible energies, maybe even the atom, energies that could ultimately hurl us to other worlds in some sort of spaceship.’
      • ‘Bohr and Heisenberg are among the first to realize that in splitting the atom mankind has acquired the power to destroy itself.’
      • ‘America rose up and rebelled, and then expanded in power until it tipped the balance during World War One and harnessed the power of the atom to win World War Two.’
      • ‘In 1900 nobody could have anticipated 80% of France's electrical power would come from a source not known at that time: the atom.’
      • ‘It all started with the discovery of the atom, and how splitting it could release vast amounts of energy.’
      • ‘After all, they had lived at the end of fifty years of fantastic technological advancement, with powered flight becoming common, the power of the atom having been harnessed and computers having been created.’
      • ‘They showed us how to split the atom and harness nuclear fuel so that we might finally meet them as equals.’
      • ‘The towering mushroom cloud is usually regarded as a symbol of the Nuclear Age, but in fact this phenomenon was first witnessed eighty-five years ago, before the power of the atom was recognised or released.’
      • ‘Written as a memoir, the book provides his unparalleled insight into the use and abuse of the power of the atom.’
      • ‘Will they turn the awesome power of the atom upon themselves as we have done?’
      • ‘Rutherford knew that alpha particles, which readily pierced the atom's cloud of electrons, didn't have enough energy to penetrate and pry apart the nucleus.’
      • ‘Over the centuries, people have turned to steam, to coal, to oil, even to the atom for their energy.’
      • ‘Heisenberg is already very famous as a scientist, and when the war starts, he will work for the Nazis trying to split the atom and develop an atomic bomb.’
      • ‘‘Today we're just going to learn about atom splitting,’ she started off.’
      • ‘It's 60 years ago tomorrow since the world became aware of the awesome destructive power of the atom.’
      • ‘When the atom's potential was realized, physicists and nuclear engineers became a kind of protected species.’
    2. 1.2usually with negative An extremely small amount of a thing or quality.
      ‘I shall not have one atom of strength left’
      • ‘You wonder how she doesn't deflate like a ruptured balloon at the end of every song; she seems to throw every atom inside her into each note.’
      • ‘It is still a spillage and by the terms of the sign even the spillage of one atom's worth of petrol should be reported.’
      • ‘Leibniz, meanwhile, believed every atom in the universe to have a soul, the universe being a projection through them of God's will, like a cosmic hologram.’
      • ‘I feel with every atom of my body that it's untrue and wrong.’
      • ‘Immaculata, 19 years old and high-strung, appears at my bedroom door, hands on hips and nostrils flaring, every atom of her quivering with melodrama.’
      • ‘She says that the Supreme One is present in every atom of this world.’
      • ‘Burning determination gripped every atom of his being.’
      • ‘But they know me, every atom of my body, every hair on my head, and they pull me, each one of them, like a multitude of collapsed stars pulling all surrounding light into them forever.’
      • ‘Every atom of me still wants to hold on to those childish beliefs that sometime in the future it will all be different.’
      • ‘He was their property, heart and soul, body and blood; what they did claimed every atom of him, sleeping and waking; it colored life and dictated the terms of death.’
      • ‘Staring at the endless universe, looking at the twinkling stars and pondering the infinitesimally tiny atom of matter or the gene that makes us up, helps to put issues of religion in true perspective.’
      • ‘Instead I just stood and stared at the sign and remembered their halcyon days when I loved them with every atom of my being.’
      • ‘Was this, as I suspected in every atom of my being, a cooked sausage that just wasn't properly cooked?’
      • ‘It is the height of hypocrisy for him to complain that Darwinism lacks causal specificity when his own theory lacks any specificity, including one atom of historical concreteness.’
      • ‘I will not fail to bring to your notice that this transaction is hitch free and that you should not entertain any atom of fear as all required arrangements have been made for the transfer.’
      • ‘Every particle, every atom of me is alive in some way I cannot explain.’
      particle, molecule, bit, little bit, tiny bit, tiny piece, fragment, fraction, grain, granule, crumb, morsel, mite, mote, speck, spot, dot
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Late 15th century: from Old French atome, via Latin from Greek atomos ‘indivisible’, based on a- ‘not’ + temnein ‘to cut’.