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Physics vocabulary · Quantum and Modern Physics

Quantum

Meaning in physics, with examples

/ˈkwɑːntəm/nounCommon term

In physics, quantum means: The smallest separate amount of a physical quantity, such as energy, that can be absorbed or emitted. Light energy, for example, comes in quanta called photons.

In Turkish: kuantum

How it is used

The plural is 'quanta'. The word is used even more often as an adjective: quantum physics, quantum mechanics, quantum number, quantum state. 'Quantised' means a quantity can only take certain separate values, like the energy of an electron in an atom.

Example sentences

  1. Planck proposed that energy is emitted in small packets, each one a quantum.

  2. In quantum mechanics, the energy of an electron in an atom is quantised.

Common collocations

  • quantum mechanics
  • quantum physics
  • quantum number
  • quantised energy
  • photonA single packet, or quantum, of electromagnetic energy. Its energy depends only on the frequency of the radiation: E = hf, where h is Planck's constant.
  • energy levelOne of the fixed amounts of energy that an electron in an atom is allowed to have. Electrons move between levels by absorbing or emitting photons.
  • photoelectric effectThe release of electrons from a metal surface when light of high enough frequency shines on it. It showed that light energy comes in packets called photons.
  • uncertainty principleA rule of quantum physics stating that certain pairs of quantities, such as a particle's position and momentum, cannot both be known exactly at the same time.
  • wave-particle dualityThe idea that light and matter can behave both as waves and as particles, depending on the experiment. Electrons, for example, can produce interference patterns.

More terms: Quantum and Modern Physics

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