quantum number

1. any integer or half of an odd integer that distinguishes one of the discrete states of a quantum-mechanical system.
2. any number that distinguishes among different members of a family of elementary particles.
[1915-20]

* * *

      any of several quantities of integral or half-integral value that identify the state of a physical system such as an atom, a nucleus, or a subatomic particle. Quantum numbers refer generally to properties that are discrete (quantized) and conserved, such as energy, momentum, charge, baryon number, and lepton number.

      The principal quantum number for electrons confined in atoms, for example, indicates the energy state and the probability of finding the electrons at various distances from the nucleus. The larger the principal quantum number, which has integral values beginning with one, the greater the energy is and the farther the electron is likely to be from the nucleus. The principal quantum number and three others are sufficient to characterize uniquely each electron in an atom. Another set of quantum numbers characterizes the atomic nucleus.

* * *


Universalium. 2010.

Look at other dictionaries:

  • Quantum number — Quantum numbers describe values of conserved numbers in the dynamics of the quantum system. They often describe specifically the energies of electrons in atoms, but other possibilities include angular momentum, spin etc.Since any quantum system… …   Wikipedia

  • quantum number — n. a number expressing the magnitude of a physical quantity in units appropriate to a given quantum mechanical system …   English World dictionary

  • quantum number — One of a set of numbers describing possible quantum states of a system, e.g., nuclear spin. See principal quantum number spin …   Dictionary of automotive terms

  • quantum number — kvantinis skaičius statusas T sritis Standartizacija ir metrologija apibrėžtis Skaičius, reiškiantis diskrečiąją fizikinio dydžio vertę, kuri apibūdina kvantinę sistemą (atomą, branduolį, molekulę) ir atskirą elementariąją dalelę. atitikmenys:… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

  • quantum number — kvantinis skaičius statusas T sritis chemija apibrėžtis Skaičius, išreiškiantis diskretinę vertę dydžio, apibūdinančio kvantinę sistemą (atomą, branduolį, molekulę) ar elementariąją dalelę. atitikmenys: angl. quantum number rus. квантовое число …   Chemijos terminų aiškinamasis žodynas

  • quantum number — kvantinis skaičius statusas T sritis fizika atitikmenys: angl. quantum number vok. Quantenzahl, f rus. квантовое число, n pranc. nombre quantique, m …   Fizikos terminų žodynas

  • quantum number — noun One of certain integers or half integers that specify the state of a quantum mechanical system (such as an electron in an atom) …   Wiktionary

  • quantum number — integer or half integer that describe the level of energy of particles according to the quantum theory …   English contemporary dictionary

  • quantum number — quan′tum num ber n. phs any integer or half of an odd integer that distinguishes one of the discrete states of a quantum mechanical system …   From formal English to slang

  • quantum number — /ˈkwɒntəm nʌmbə/ (say kwontuhm numbuh) noun one of a set of integers or half integers which defines the energy state of a system, or its components, in quantum mechanics …   Australian English dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.