The pr esent accepted value of electrical charge is 1. These are the same relations we have for the photon, but for. Preface to german translation in the three years between the publication of the original french version, as translated to english below, and a german translation in 19271, the development of physics progressed very rapidly in the way i foresaw, namely, in terms of a fusion of the methods. In 1905, einstein suggested that light has a dual character, and behaves both as a particle and a wave. How bohrs model of hydrogen explains atomic emission spectra. Compare with compton wavelength of the particle formally speaking, c. What is the debroglie wavelength of a 125 g baseball moving at 28. Mungan, spring 2009 in this brief note i show that the quantum length, equal to the cube root of the quantum volume which in turn is the reciprocal of the quantum concentration, given by. If an input is given then it can easily show the result for the given number. Download ncert books 202021 and offline apps based on new cbse syllabus 202021. We can take the average interparticle spacing in the gas to be approximately vn where v is the volume and n is the number of particles. Millikan 18681953 devised a method known as oil drop experiment 190614, to determine the charge on the electrons. Basing his formula on earlier formulas, he arrived at the equation below. So a free particle with momentum p can be associated to a waveto a plane wave, in factplane wavewith.
A proton is accelerated through a potential difference v. Instead of using wavelength, its more convenient to deal with wave number itexkitex, which in one dimension is related to wavelength through. Find the wavelength of an electron moving with a speed of ms1. With the addition of two new quantum numbers, the bohrsommerfeld theory accounted for many features of spectra and showed how the periodic table is built up in a systematic way. Physics notes class 12 chapter 11 dual nature of radiation and matter cathode rays cathode rays are the stream of fast moving electrons. Moving double slits, composite mass, and clock synchronization. The same formula gives the momentum of an individual photon associated with a light wave of wavelength. This work is licensed under a creative commons attributionnoncommercialsharealike 4.
If the potential energy is independent of time, as we have written above, we can separate eq. This equation simply relates the wave character and the particle character of an object. By rearranging the momentum equation stated in the above section, we find a relationship between the wavelength. Its dual behavior is partly explained by 1doubleslit experiment of thomas young who represents the photons motion as a wave and also by 2the photoelectric effect in which the photon is considered as a particle. Before i derive the equation, it is important to understand the debroglie hypothesis which i am sure.
Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. What happens to a high energy photon after it strikes an electron. Dual nature of radiation wave theory of electromagnetic radiation explained the phenomenon of interference, diffraction and polarisation. But then, the wave nature of electromagnetic radiation is called into question when it is involved in blackbody radiation, photoelectric e. Properties of cathode rays i cathode rays are not electromagnetic rays. On the other hand, photoelectric effect supported particles nature of light. Physics notes class 12 chapter 11 dual nature of radiation.
Quantum physics i, lecture note 4 mit opencourseware free. For a wavelength in nanometers the value in meters must be multiplied by 10 9. But then, the wave nature of electromagnetic radiation is called into question when it is involved in blackbody radiation, photoelectric e ect and such. The debroglie wavelength the lorentz transformation had been postulated for electromagnetic waves before einstein developed special relativity. Thus, every object in motion has a wavelike character. What is the difference between the debroglie and compton. The debroglie equations can be derived from the einsteins famous equation of energymass equivalence and planks theory of quantum radiation. Computing debroglie wavelengths we usually quote the energy of a particle in terms of its kinetic energy in electron volts, ev or million electron volts, mev.
Bohr model energy levels derivation using physics bohr model energy levels. A primitive form of this equation was derived by the student in the examination. An alternate and also correct version of this formula is. On substituting the energy on thermal neutron on wavelength of the neutron, we get, on applying the equipartition theorem and the ideal gas equation, we render to the derivation where the lambda is. Ncert solutions for class 12 physics chapter in pdf form to free download. After all, the world would be a mighty strange place if baseballs and ostriches had wavelengths large enough that you could observe their diffraction patterns. The relationship is now known to hold for all types of matter. Ncert solutions for class 12 physics chapter 12 atom pdf.
These rays are produced in a discharge tube at a pressure below 0. Quantum physics i, lecture note 4 free online course. For example, the phase of an em wave at some point is the same as at the lorentz transformed point. Phase velocity and group velocity for beginners in the first section of this paper i derive the formulas for the phase velocity and group velocity as a function of the total relativistic energy and the momentum of a particle. Democritus the atomic theory of matter has a long history, in some ways all the. This means that photons, electrons possess both momentum as well as wavelength.
Light and its nature have caused a lot of ink to flow during these last decades. Ncert solutions for class 12 physics chapter 12 atom in pdf form are given below to free download. Dec 04, 2014 the compton wavelength is a quantum mechanical property of a particle. Square potential barrier university of texas at austin. Because people thought, anyway light is waves so the surprising thing that would be that matters are waves. Bohr model radii derivation using physics bohr model radii. An electron and a proton are possessing same amount of k. The reason for this is that particles are usually accelerated to some energy by an electric field. The same formula gives the momentum of a photon or wavelength translations. It was introduced by arthur compton in his explanation of the scattering of photons by electrons a process known as compton scattering.
Electron microscope is a common instrument illustrating this fact. Sommerfeld refined bohrs theory by incorporating special relativity and the possibility of elliptical orbits. Very low mass particles moving at speed less than that of light behaves like a particle and wave. The plane matter waves of a free particle moving with speed v has the form. When i conceived the first basic ideas of wave mechanics in 19231924, i was guided by the aim to perform a real physical synthesis, valid for all particles, of the coexistence of the wave and of the corpuscular aspects that einstein had introduced for photons in his. Chapter 41 wave mechanics national tsing hua university. Derivation of the debroglie wave relation stack exchange. The em waves were entirely consistent with relativity. Derivation of the wave equation most of you have seen the following in your physics 2324 or equivalent sequence. Matter wave simple english wikipedia, the free encyclopedia. Ncert solutions for class 12 physics chapter nuclei pdf.
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