using the de Broglie Wavelength of an electron, explain why there are "shells" of electron density:?
960070
Two dimensions should be explanation enough. Assume the de Broglie wavelength of an electron is some distance in nanometers. If we draw the nucleus as a dot and draw the electron as a continuous wave around the nucleus, the wave has to be the length of some multiple of its wavelength. If the wave were not the length of a discrete multiple of its wavelength it would not be continuous because a full circle's rotation would cause the wave to jump. If we constrain the atomic model to behave like this, then the answer is simple. \n\nConsider the electron wave that is four wavelengths long. This wave is a function which describes electron density. The next energy level has to correspond to a wave that is five wavelengths long. In this way, the wave cannot increase gradually, but rather the levels are split into discrete shells, one for each number of wavelengths in the wave.
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radiation according to me is due to excitation of electrons from lower energy levels to higher levels and vice versa.During exitation electrons obsorb or release energy in form of packets called quanta which will travel in form of waves
642453
proton and neutron, the electrons are on the outer shell
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Be careful with your statement.  The electrons do not act like both a wave and particle at the same time!  They act like one or the other.\n\nWhen you are not "watching" the electrons, they exhibit wave like behavior because they hit on the screen only in the spots that would correspond to a bright fringe for light.  But, that isn't the coolest part.  \n\nFirst: you can shoot one electron at a time, and each time, each electron will hit at a spot that would be a bright fringe, if you were to shoot light with the same wavelength through two slits.  Now, cover one of the slits and shoot one electron at a time, and the pattern will shift to that of a single slit diffraction. \n\nQuestion: How does the electron "know" if there are two slits or one slit, so that it hits the correct spot on the screen?  Answer: if there are two slits open, it goes through both slits on its way to the screen!  In essence, it interferes with itself!  This is what is known as the sum of histories, where the electron is said to take every path possible on its way to the screen.  \n\nOf course, you might object and say when I shoot a cannon ball into the air, it only takes one path: the parabolic curve.  So, why does an electron take every path and the cannon ball does not?  This is the essence of quantum physics: these bizzare happenings occur with the very small.  However, the sum of histories can still be applied to a cannon ball, but guess what?  All paths cancel except for the parabolic path it will always take on Earth.  For the electron, each path has equal probability, so they do not cancel, thus it goes through both slits at the same time.\n\nSecond: If you try to "watch" the electron go through both slits by using an instrument, the electron stops acting like a wave, and behaves like a particle.  It hits the screen like a particle should.  Stop "watching" it and the pattern goes right back to that of wave interference!\n\nIt's as if nature will not allow us to see such bizarre things.
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This is a more complicated question than it appears.  You didn't include to what degree you were seeking this information, so rather than go into a great deal of explanation I have included a link that explains and tabulates the basics of electron energy levels.  Hope this helps.
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It all comes down to two forces: the attraction between electrons and the nucleaus and the repulsion between the individual electrons.  This leads to a complex set of equations that do not have a solution. \n\nIf we assume that molecules behave as a combination of atomic states of only one electron, then we can try to formulate solutions of the equations (because the electron-electron repulsion term is zero). \n\nUnfortunately, the equations do not have a single answer. They have multiple answers. These answers have been called electronic configurations and are your different shells, sub-shells, etc. The actual quantum numbers are seen in the equations as solutions to the Schroedinger equation(HY=EY): n, l, ml, and ms.\n\nThe prevailing intepretation are that these states are energy levels which can be occupied by electrons as the form molecular bonds. \n\nMy university professor would probably remove my liver for such a poor description of the phenomenon, but this was always my best understanding of it.
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Bohr's theory states that each level that the electron of hydrogen can be promoted to from the ground state are of specific energy (ie the are quantized). When an electron moves between these levels, it either absorbs or emits energy that corresponds to the energy level that the electron is moving to. The spectral lines you are talking about are the emitted radiation caused by electrons that are moving back to the ground state. They can be used to work out how much energy the levels have.
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The basic physics behind a laser was thought up by Einstein (that guy was everywhere!) but the first ones were not actually built until the middle of the 20th century.\n\nLaser is an acronym for Light Amplification via Stimulated Emission of Radiation. "Radiation" just means light, and "Stimulated Emission" is a property of some gases because of Quantum Mechanics.\n\nIn QM we know that electrons can only be in certain "orbit" in an atom, more properly called energy levels. When an electron makes a quantum leap from one energy level to another lower level (assuming there is a lower level) It will release a photon (sort of a piece of light) with a very specific frequency. (Frequency and wavelegth are inversely proportion, so one frequency corresponds to one wavelength.)\n\nFor example in hydrogen if an electron in the second lowest energy level drops down to the very lowest level it will emit a photon with a wavelength of 656.3 nanometers, which turns out to be reddish light. From the third lowest to the lowest the photon wavelength is 486.1 nm, which is blue green.\n\nThe point being that an atom can emit light only in very precise frequencies, and not any old frequency.\n\nEinstein developed the concept of "stimulated emission" which is a much more complicated consequence of Quantum Mechanics. It says that if a photon with a transition wavelengh passes close to an excited atom, it will "stimulate" the excited atom to also emit at that frequency.\n\nSo in the hydrogen example, lets say the electron is in the 3rd level. If it were to drop to the lowest level the photon would be 486 nm. While the electron is just hanging around on the third level, if some random photon comes flying past with a wavelength of 486 nm this will stimulate the electron to drop and emit its own photon of that frequency. From the outside it looks like one photon went past an atom and then there were two photons.\n\nTherefore the idea in a laser is to get a lot of atoms into an excited state - which is hard, they would rather be in their ground state - and then wait for one of the atoms to emit a photon. This will prompt more atoms to emit photons, and all those will prompt even more to emit photons, etc. etc. The result being "light amplification via the process stimulated emission."\n\nThe benefits of a laser include the light being all very nearly at one wavelength, and all the light being in phase.\n\nFor a CO2 laser the output light has a wavelength of 10,600 nm, which is in the infrared part of the spectrum and not visible to the human eye. The gas inside a CO2 laser consists of, well, CO2 and also Nitrogen and Helium. The transitions are not simple atomic ones as in the example of hydrogen I gave, but molecular transitons of the CO2 molecule. The basic physics is the same, though.\n\nThese other gases are needed as part of the difficult process of getting a lot of the CO2 molecules into an excited state and keep them there long enough so that they will emit photons via the stimulated emission process.
128025
This is a relativistic problem The answer depents on the viewpoint of the observer. oscillation is a factor of time-mass-energy all of which are distorted relativisticaly. you are probably looking at an inverse square solution.\n\nContrary to popular belief electrons do not travel at relativistic velocities only their electromagnetic wave. This problem is further out there than you think.
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Its actually derived from Maxwell's Wave Equations, see source. Its too complex and requires mathematic symbols, so I can't type it here.
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De Broglie wavelength L = (h/mv) sqrt( 1-v^2/c^2).\n\nSquare, solve for v = hc /sqrt(mc^2 L^2 + h^2) \nH = Planck's constant\nc = the speed of light\nm = mass
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It is because a a shell can occupy only a maximum of 8 electrons which satisfies the octet rule.\n\n the rules are:\nHUND's rule of maximum multiplicity\nPAULI's exclusion principle\nAUFBAU principle
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Maybe this explanation can help? http://en.wikipedia.org/wiki/Spectral_density
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Most physicists (like Feynman) will tell you it's definitely a particle.  I think they're full of crap, and it's a wave.  The fact that it can only be absorbed and emited in discrete packets doesn't necessarily mean that it really travels as a particle, and the notion of a particle flies in the face of the double-slit one-photon experiment.
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There is no room for them to fit.  the charge capacity of each shell is fixed and thus so is the number of electrons in it.  It is the charge of the outer most shell which determines the carachteristics of the atom, and it's nucleus determines it weight.  All in balance.
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It is harder to remove an electron that has more than 1 electron in the shell because of the combined energy that the shell has. A single electron itself does not require a lot of energy to remove, however, when there is more than one, there is combined energy placed in the shell. It is still possible to do so, but is very hard.\n\nTom Walvin\nChemist
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The movement of an electron from one place to another.