Definition of atomic weight in US English:

atomic weight


  • another term for atomic mass
    • ‘Atoms of an element that have the same atomic number but a different atomic weight are referred to as isotopes.’
    • ‘Finding that the isotopes of neon have atomic weights that are whole numbers vindicated Prout's hypothesis that hydrogen was the basis for all the elements.’
    • ‘In general the molecular weight of a molecule is the sum of the atomic weights of its constituent atoms.’
    • ‘It has an atomic number of 101 and an approximate atomic weight of 258.’
    • ‘Hydrogen is the lightest element, so it provides a convenient unit for measuring the relative atomic weights of the other elements.’
    • ‘The sum of the atomic mass of the protons and neutrons determines the atomic mass or atomic weight of the nucleus.’


atomic weight

/əˈtɑmɪk weɪt//əˈtämik wāt/