Definition of atomic theory in US English:

atomic theory


  • 1The theory that all matter is made up of tiny indivisible particles (atoms). According to the modern version, the atoms of each element are effectively identical, but differ from those of other elements, and unite to form compounds in fixed proportions.

    • ‘Dalton's atomic theory has been refined many times.’
    • ‘Early atomic theory assumed that atoms were indivisible.’
    • ‘His first contribution to chemistry was an early version of atomic theory.’
    • ‘From this perspective, modern atomic theory is extraordinarily simple.’
    • ‘For example, Bohr's atomic theory includes terms like quantum numbers, quantum jump, steady state, and explains spectra described with the help of wavelength.’
    • ‘There he worked with Born on atomic theory, writing a joint paper with him on helium.’
    • ‘Essentially, Lavoisier's definition is in agreement with contemporary atomic theory.’
    • ‘Together they are considered as the joint founders of atomic theory.’
    • ‘And while modern science has progressed far beyond classical atomic theory, it nevertheless continues to understand the world in terms of the discrete.’
    • ‘In the early days of modern atomic theory, the idea of diatomic molecules seemed counter-intuitive.’
    • ‘We don't know everything there is to know about atomic theory.’
    • ‘In 1908, Ostwald published his acceptance of atomic theory, since Perrin's experiments had proved that molecules actually do exist.’
    • ‘While experimenting with air, Boyle began to promote his atomic theory, which is the foundation for our modern understanding of matter.’
    • ‘Further, this series assumes an understanding of basic chemistry, and a grasp of current basic atomic theory, such as the properties of protons, electrons, etc.’
    • ‘The existence of neutrons, and the discovery that some elements vary in the number of neutrons they have, lead to the integration of atomic theory and observations of radioactivity.’
    • ‘Visitors will progress along a timeline of discovery, featuring the most significant breakthroughs, from atomic theory to current science developments such as robotics and scarless tissue healing.’
    • ‘Epicurus adopted the atomic theory of Democritus, who taught that in a universe of colliding atoms there could be no room for divine activity.’
    • ‘It was clear from these letters that Einstein had talked about the issues of relativity, and atomic theory and everything else, but especially relativity, with Mileva.’
    • ‘In the seventeenth century, as scientists and philosophers started turning to empirical research in order test their theories, atomists approached atomic theory as a key to nature's secret.’
    • ‘It played a major role in the unification of chemistry, comparable to that of the great impact made by atomic theory in the previous century.’
    1. 1.1 In any field, a theory that proposes the existence of distinct, separable, independent components.
      ‘an atomic theory of heredity’
      • ‘In effect, it was an atomic theory of heredity.’
      • ‘The two chief causes of anxiety were fear of the gods and fear of death, so Epicurus sought to nullify both of these by teaching an evolutionary atomic theory.’
      • ‘During the year of 1801, Dalton addressed an atomic theory of how air was not a complex substance but it was a mixture of oxygen and nitrogen.’
      • ‘Kant, a believer in an atomic theory of the exterior world, nonetheless came to believe that we could have no direct and certain knowledge of that world.’
      • ‘It was described in European books of the nineteenth century, which set chess hobbyists to analyzing the elements of the moves of chess-pieces, resulting in an atomic theory of chess and an explosion of new pieces and combinations.’


atomic theory

/əˈtɑmɪk ˈθɪəri/