9 lines
699 B
Markdown
9 lines
699 B
Markdown
[[Modern Physics]]
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# Summary
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* Quantum theory developed because classical physics can't explain atomic spectra, blackbody radiation or photoelectric effect.
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* Photons are electrically neutral massless particles.
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* $E=hf$, with $h$ being Planck's constant.
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* Photons travel at $c=$ 299792458 m/s (or $c=3*10^8$ for simplification) in a free space, and are slowed by a factor of the medium's index of refraction.
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* Particles like electrons show wave behavior, quantified by de Broglie wavelength $\lambda=h/p$. Wavelength increases as momentum decreases.
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* Quantum effects matter when a particles de Broglie wavelength is comparable to the system.
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* In bound systems, energy and momentum are discrete. |