The assertion that no two fermions can have the same quantum number.
- ‘Fermions obey the Pauli exclusion principle, which means that two of them cannot occupy the same quantum state.’
- ‘In addition to electrons, the Pauli exclusion principle applies to all sub-atomic particles with half-integral spins, known as fermions, such as neutrons and protons.’
- ‘For electrons, the Pauli exclusion principle paradoxically leads to an effective attraction that balances the particles' electrostatic repulsion at short distances.’
- ‘There are so many unoccupied electron states in metals that an electron can wander freely without being limited by the Pauli exclusion principle.’
- ‘That's a more precise statement of the Pauli exclusion principle.’
1920s: named after W. Pauli (see Pauli, Wolfgang).
We take a look at several popular, though confusing, punctuation marks.