4/20/2024 0 Comments Louis de broglie atomic theory![]() ![]() Energy in excess is released as kinetic energy in the ejected photoelectron and is proportional to frequency of light. Photelectrons are released when photon energy (hv) is greater than the work function. The photoelectric effect can occur even with the lowest frequency light called the threshold frequency. Threshold frequency: V o= (eV o)/h = work function/Planck's constant In order to emit more electrons, the light source must be brightened to increase intensity, which still maintains frequency of light and same energy, but increases the number of photons. However, if the photon reached the threshold frequency it could cause one electron to be emitted. ![]() He concluded that if the threshold frequency of the metal was greater than the frequency of the photon, then the photon will have no effect when it bombards the metal surface. Increase frequency->Increases kinetic energy of electronsĮinstein explanation was that light had the characteristic of a particle (photon) with the photon energy of E=hv. Increase brightness (maintains frequency and energy)->Increases Intensity (increases#of phot ons)->Increases # of electrons emitted But it doesn't matter how much energy is increased or how much you increase the amplitude when it comes to trying to emit electrons from a metallic surface. The energy output will be greater and when this happens the amplitude of the light wave increases. So by increasing brightness, intensity increases, and so does energy released. ![]() In other words, the intensity can be described as the brightness from a source of light. The amount of electrons ejected is determined by the intensity of the incident light, however, the frequency of the light effects the kinetic energies of the emitted electrons. This process holds true when the incident light has a higher frequency than a certain threshold value. The photoelectric effect phenomenon that electrons are emitted when light strikes the surface of metals was discovered by Heinrich Hertz in 1888. Planck's equation: E=hv Planck's constant: h=6.626x10 -34 Js Einstein's idea was revolutionary because he brought a new perspective at looking at light not only as a wave, but as a particle. This equation states that the frequency and energy of a quantum of electromagnetic radiation are proportional. Lewis), were "particles of light" that had similar energy to that of Planck's equation. In 1905 he declared that photons (named by G.N. ![]() De Broglie became the first high-level scientist to call for establishment of a multi-national laboratory, a proposal that led to the establishment of the European Organization for Nuclear Research ( CERN).\)Īlbert Einstein showed that the dependence on frequency could not be justified by the classical wave theory alone, so he provided a particle perspective. Louis de Broglie was the sixteenth member elected to occupy seat 1 of the Académie française in 1944, and served as Perpetual Secretary of the French Academy of Sciences. The pilot-wave model and interpretation was then abandoned, in favor of the quantum formalism, until 1952 when it was rediscovered and enhanced by David Bohm. The 1925 pilot-wave model, and the wave-like behaviour of particles discovered by de Broglie was used by Erwin Schrödinger in his formulation of wave mechanics. Recherches sur la théorie des quanta ("Research on Quantum Theory") (1924)ĭe Broglie won the Nobel Prize for Physics in 1929, after the wave-like behaviour of matter was first experimentally demonstrated in 1927. (BA in History, 1910 BA in Sciences, 1913 PhD in physics, 1924) ![]()
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