Definition of quantum number in English:

quantum number


  • A number which occurs in the theoretical expression for the value of some quantized property of a subatomic particle, atom, or molecule and can only have certain integral or half-integral values.

    • ‘Similar orbital schemes may be constructed for larger values of the principal quantum number.’
    • ‘However, in the early 50s Murray Gell-Mann suggested that these new particles had a conserved quantum number which he called ‘strangeness.’’
    • ‘Each quantum number describes the value of a property of the electron.’
    • ‘The principal quantum number tells us how far from the nucleus a certain electron is, i.e. what level it occupies, the greater is n, the farther it is from the nucleus.’
    • ‘In the quantum mechanical model, the energy of the ground state (or the lowest energy level possible in the molecule) is not zero, but a finite quantity which is a function of Planck's constant and the vibrational quantum number.’