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Toshkent farmatsevtika instituti fizika, matematika va axborot texnologiyalari kafedrasi
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| bet | 52/69 | | Sana | 19.03.2017 | | Hajmi | 172.07 Kb. | | #410 |
Pauli Exclusion Principle:
The prohibition on two identical fermions from sharing the same quantum state simultaneously. Among other implications it stops electrons (which are a kind of fermion) from piling on top of each other, thereby explaining the existence of different types of atoms and the whole variety of the universearound us.
Photoelectric Effect:
The phenomenon in which, when a metallic surface is exposed to electromagnetic radiation above a certain threshold frequency (typically visible light and x-rays), the light is absorbed andelectrons are emitted. The discovery of the effect is usually attributed to Heinrich Hertz in 1887, and study of it (particularly by Albert Einstein) led to important steps in understanding thequantum nature of light and electrons and in formulating the concept of wave-particle duality.
Photon:
A particle (or quantum) of light or other electromagnetic radiation, which has no intrinsic mass and can therefore travel at the speed of light. It is an elementary particle and the basic unit of light, and effectively carries the effects of the electromagnetic force. The modern concept of the photon as exhibiting both wave and particle properties was developed gradually by Albert Einstein and others.
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