emission
Quick Summary
Emission, in physics, refers to the release of energy or particles from a substance. This can occur in several ways:
- Spontaneous Emission: An atom in an excited, high-energy state releases a photon and transitions to a lower energy state. This is a probabilistic event, typically happening within 10-9 to 10-8 seconds.1
- Stimulated Emission: The presence of a photon with specific energy can trigger an excited atom to emit an identical photon, transitioning to a lower energy state. This process is crucial for technologies like lasers.23
- Electron Emission: Electrons are released from a substance through processes like photoelectric, thermionic, or radioactive activity, or solely due to an electric field (field emission).45
Emission can also refer to electromagnetic radiation from celestial bodies or substances discharged into the air.67
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lightEmission and absorption processesThat materials, when heated in flames or put in electrical discharges, emit light at well-defined and characteristic frequencies was known by the mid-19th century. The study of the emission and absorption spectra of atoms was crucial to the development…
Read MoreThat materials, when heated in flames or put in electrical discharges, emit light at well-defined and characteristic frequencies was known by the mid-19th century. The study of the emission and absorption spectra of atoms was crucial to the development…
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electromagnetic radiationGeneration of electromagnetic radiation…say that any system which emits electromagnetic radiation of a given frequency can absorb radiation of the same frequency.
Read More…say that any system which emits electromagnetic radiation of a given frequency can absorb radiation of the same frequency.
Read More- electromagnetic radiationResonance absorption and recoil
…recoil momentum during absorption and emission of the gamma photon is taken up by the whole solid (or more precisely by its entire lattice). This then reduces the recoil energy to nearly zero and thus allows resonance absorption to occur even for gamma rays.
Read More…recoil momentum during absorption and emission of the gamma photon is taken up by the whole solid (or more precisely by its entire lattice). This then reduces the recoil energy to nearly zero and thus allows resonance absorption to occur even for gamma rays.
Read More - radiationAbsorption and emission
In transit through matter, the intensity of light decreases exponentially with distance; in effect, the fractional loss is the same for equal distances of penetration. The energy loss from the light appears as energy added to the medium, or what is known as absorption.…
Read MoreIn transit through matter, the intensity of light decreases exponentially with distance; in effect, the fractional loss is the same for equal distances of penetration. The energy loss from the light appears as energy added to the medium, or what is known as absorption.…
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