What was Niels Bohr's apparatus or experimental set up for making his theory?
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Basically, this is it -\n\nIn atomic physics, the Bohr model depicts the atom as a small, positively charged nucleus surrounded by waves of electrons in orbit — similar in structure to the solar system, but with electrostatic forces providing attraction, rather than gravity, and with waves spread over entire orbits instead of localized planets.\n\nThe Bohr model is a primitive model of the hydrogen atom that cannot explain the fine structure of the hydrogen atom nor any of the heavier atoms. As a theory, it can be derived as a first-order approximation of the hydrogen atom in the broader and much more accurate quantum mechanics.
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that's a very broad question. because all the branches of physics are intertwined with each other.\nUmm.. a basic principle of quantum theory is the observation that the smallest pieces of matter, electrons,  exhibit properties of both particles and waves. What an electron is doing at any given moment is a mystery to all of us. We can't just "look" at what the electron is doing to find out, though. The problem is that when we look at something, we're bombarding the electron with photons (light particles that have no mass, but carry momentum & energy).  Hitting the electron with a photon changes the path, speed, etc of the electron and defeats the whole purpose of looking at it.\nInstead we have to look at the end results of what electrons do - so there is an experiment called the double slit experiment which shows us where electrons hit a detector after passing through two small slits. \nYou might imagine that throwing electrons that passed through two holes would create two big blotches on the detector. \nBut the results of this experiment showed that the electrons hit the detector in a particular way - one that demonstrated that the path the electrons took was determined by wave-like motion, not like particle motion (diffraction).\nWierd - so actually, what we conclude is that the electrons took EVERY possible path from the source to the detector, and then upon observation, the resulting pattern arranged itself according to a probability distribution.  Strange, yes.\nAnyway, exploiting the fact that electrons' actions are governed by probability, we are able to conclude a lot of rules about electrons. Where they are, what their energy is, what their momentum is, .. all related to probability. And also all related to "standing waves."  (very very complicated mathematics go here) \nThe thing about standing waves (imagine a violin string) is that they can vibrate at certain harmonics - either one half wave across the whole string, or one, or one and a half, as long as both ends are clamped down.  But they can never be in between those. (Try it by shaking a rope faster and faster)\nANYWAY so this tells us that the amount of energy that electrons can carry can only be in certain amounts and never in between. When an electron gains or loses energy, it can only be enough to send it to the next lowest/highest energy level. Never in between.  This is known as quantization, and you may know this as the "energy states" of electrons.
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Neils bohr suggested that the nucleus was positively charged and the electrons were negatively charged. The electrostatic force between them kept electrons in their orbits. The electrons moved in specific orbits only. They did not radiate energy continously but in the form of many quanta (packets) of energy. Electron emitted energy only when it jumped from a higher orbit to a lower orbit.\n\nMathematics of Bohr's atomic model :\nLet charge on proton be e and that on electron be -e. Let radius of the nth orbit be r. The electrostatic force between nucleus and the electron provides the electron a necessary centripedal force. Let the velocity of the electron be v and mass be m.\n\n m(v^2)/r = k(e^2)/(r^2)    where k = 1/(4*pi*epsilon)\n                         epsilon is permittivity of space \n\nThis is the first postulate of his theory.\n\nElectrons move only in those orbits whose angular momentum is an integral multiple of h/2pi where h is plank's constant\n\n  mvr = Iw = nh/(2*pi)\n\nI - moment of inertia of electron\nw - angular velocity of electron.\n\nThis is the second postulate.\n\nLet the energy of the initial orbit of electron be E2 and the energy of final orbit be E1. Then when it jumps from initial orbit to the final orbit, the energy liberated is in the form of radiations having frequency f and is numerically equal to the difference in energies of the two energies of electron in the two orbits.\n\n                dE = E2 - E1\n\nHence,          hf = E2 - E1\n where h is plank's constant.\n\nThis is the third postulate.\n\nI hope this solves your query. Post your queries if you feel unsatisfied.
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Try the sonometer or the resonance experiment
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Austrian researchers have teleported photons (particles of light) across the Danube River in Vienna using technology that calls to mind Scotty beaming up Captain Kirk in the science fiction series. \n\n\n"We were able to perform a quantum teleportation experiment for the first time ever outside a university laboratory," said Rupert Ursin, a researcher at the Institute for Experimental Physics at the University of Vienna in Austria. \n\nThe researchers read the "blueprints" of the photons they wanted to teleport. They then broke up the photons into smaller particles called quantum bits and sent these bits, along with the blueprints, through a fiber-optic cable in a sewage pipe under the river.
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the theory that light, and all electromagnetic radiation (radio waves, x-rays, microwaves) travels as a wave, like the ripples on a plucked string. these waves look like sine and cosine graphs.\n\n\nthis was proved to be an incomplete picture by eistein's analysis of the photoelectric effect, for which he won the nobel prize. this showed light was in fact made of particles called photons. however, quantum wave theory now tells us that all matter is both a particle and aa wave; the matter is contained in a particle, but the location of the particle is determined by a wave.
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Laboratory implements?
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Of the atom?  Neils Bohr believed (like Rutherford) that an atom was composed of a nucleus, having a positive charge being circled by negative electrons, much like a solar system.  His model includes the ability of an excited electron to quantum jump to a high energy level and then emit radiation as it returns to its regular state.
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Among the important early researchers in X-rays were Professor Ivan Pului, Sir William Crookes, Johann Wilhelm Hittorf, Eugen Goldstein, Heinrich Hertz, Philipp Lenard, Hermann von Helmholtz, Nikola Tesla, Thomas Edison, Charles Glover Barkla, Max von Laue, and Wilhelm Conrad Röntgen.\n\nPhysicist Johann Hittorf (1824 - 1914) observed tubes with energy rays extending from a negative electrode. These rays produced a fluorescence when they hit the glass walls of the tubes. In 1876 the effect was named "cathode rays" by Eugen Goldstein. Later, English physicist William Crookes investigated the effects of energy discharges on rare gases, and constructed what is called the Crookes tube. It is a glass vacuum cylinder, containing electrodes for discharges of a high voltage electric current. He found, when he placed unexposed photographic plates near the tube, that some of them were flawed by shadows, though he did not investigate this effect.\n\nTesla\nIn April 1887, Nikola Tesla began to investigate X-rays using high voltages and vacuum tubes of his own design, as well as Crookes tubes. From his technical publications, it is indicated that he invented and developed a special single-electrode X-ray tube, which differed from other X-ray tubes in having no target electrode. He stated these facts in his 1897 X-ray lecture before the New York Academy of Sciences.\n\nThe principle behind Tesla's device is nowadays called the Bremsstrahlung process, in which a high-energy secondary X-ray emission is produced when charged particles (such as electrons) pass through matter. By 1892, Tesla performed several such experiments, but he did not categorize the emissions as what were later called X-rays, instead generalizing the phenomenon as radiant energy. He did not publicly declare his findings nor did he make them widely known. His subsequent X-ray experimentation by vacuum high field emissions led him to alert the scientific community to the biological hazards associated with X-ray exposure.\n\nHertz\nIn 1892, Heinrich Hertz began experimenting and demonstrated that cathode rays could penetrate very thin metal foil (such as aluminium). Philipp Lenard, a student of Heinrich Hertz, further researched this effect. He developed a version of the cathode tube and studied the penetration by X-rays of various materials. Philipp Lenard, though, did not realize that he was producing X-rays. Hermann von Helmholtz formulated mathematical equations for X-rays. He postulated a dispersion theory before Röntgen made his discovery and announcement. It was formed on the basis of the electromagnetic theory of light (Wiedmann's Annalen, Vol. XLVIII). However, he did not work with actual X-rays.\n\nRöntgen\nOn November 8, 1895, Wilhelm Conrad Röntgen, a German scientist, began observing and further documenting X-rays while experimenting with vacuum tubes. Röntgen, on December 28, 1895, wrote a preliminary report "On a new kind of ray: A preliminary communication". He submitted it to the Würzburg's Physical-Medical Society journal. This was the first formal and public recognition of the categorization of X-rays. Röntgen referred to the radiation as "X", to indicate that it was an unknown type of radiation. The name stuck, although (over Röntgen's great objections), many of his colleagues suggested calling them Röntgen rays. They are still referred to as such in many languages, where available see the list of titles for versions of this article in other languages. Röntgen received the first Nobel Prize in Physics for his discovery.\n\nRöntgen was working on a primitive cathode ray generator that was projected through a glass vacuum tube. Suddenly he noticed a faint green light against the wall. The odd thing he had noticed, was that the light from the cathode ray generator was traveling through a bunch of the materials in its way (paper,wood, and books). He then started to put various objects in front of the ge
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It could be said that  Friedrich Wohler began the destruction of this theory - he was a German chemist, who was the the first to synthetically produce in his lab an organic compound, urea, from\ninorganic compounds.
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You asked several questions.  My answer applies to the generation of "free electrons".\n   If you can, picture the structure of an electronic vacuum tube, the invention of which (the triode, at least) is attributed to Lee Deforest. Thomas Edison worked on  similar devices.\n1) A material (such as Thorium) is electrically heated to a temperature such that electrons are "boiled off" and are electrostatically attracted to a positively (voltage) charged "plate" in a vacuum.  This flow of free electrons is a current (amperes).\n2) These electrons are NOT recycled.  The Thorium gradually deteriorates - is worn out.  \n3)  In a similar manner, this may be a source of electrons in the devices you mention.
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Experimenting with magnetorheological fluids.\nSuspending a magnet in mid-air.\nLevitating pyrolytic graphite.\nA Gauss Rifle: A Magnetic Linear Accelerator.\nBuilding a Curie-effect heat engine.\nGoing further:\n\nSuperconductors.\n\n \n \n \nThe Gauss Rifle:\nA Magnetic Linear Accelerator\n \n \n This very simple toy uses a magnetic chain reaction to launch a steel marble at a target at high speed. The toy is very simple to build, going together in minutes, and is very simple to understand and explain, and yet fascinating to watch and to use.  \n \n gauss rifle Click on image for animated view  \n \n The photo above shows six frames of video showing the gauss rifle in action. Each frame shows 1/30th of a second. In the first frame, a steel ball starts rolling towards a magnet taped to a wooden ruler. In the second frame, a second ball can be seen speeding between the rightmost two magnets. By the third frame, the accelerator has sped up so much that the ball that is seen leaving the left side of the device is just a blur as it smashes into the target. One ball, starting at rest, has caused another ball to leave the device at a very high speed.  \n \n gauss rifle materials Click on image for larger view  \n \n The materials are simple. We need a wooden ruler that has a groove in the top in which a steel ball can roll easily. Any piece of wood or aluminum or brass with a groove will work. We chose the ruler because they are easy to find around the house or at school or at a local stationery store.  \n \n We need some sticky tape. Again, almost any kind will do. Here we use Scotch brand transparent tape, but vinyl electrical tape works just as well.  \n \n We need four magnets. Most any type will do, but the stronger the magnets are, the faster the balls will go. Here we use the super strong gold-plated neodymium-iron-boron magnets we have made available in our catalog for the other projects. They work great.  \n \n We will also need nine steel balls, with a diameter that is a close match to the height of the magnets. We use 5/8 inch diameter nickel plated steel balls from our catalog.  \n \n The only tool we will need is a sharp knife for trimming the tape.  \n \n gauss rifle first\nClick on image for larger view  \n \n We start by taping the first magnet to the ruler at the 2.5 inch mark. The distance is somewhat arbitrary -- we wanted to get all four magnets on a one foot ruler. Feel free to experiment with the spacing later.  \n \n gauss rifle tape\nClick on image for larger view  \n \n With the sharp knife, trim off any excess tape. Be careful, since the knife will be strongly attracted to the magnet.  \n \n It is very important that you keep the magnets from jumping together. They are made of a brittle sintered material that shatters like a ceramic. Tape the ruler to the table temporarily, so that it doesn't jump up to the next magnet as you tape the second magnet to the ruler.  \n \n gauss rifle two\nClick on image for larger view  \n \n Continue taping the magnets to the ruler, leaving 2.5 inches between the magnets.  \n \n When all four magnets are taped to the ruler, it is time to load the gauss rifle with the balls.  \n \n gauss rifle all\nClick on image for larger view  \n \n To the right of each magnet, place two steel balls. Arrange a target to the right of the device, so the ball does not roll down the street and get lost.  \n \n To fire the gauss rifle, set a steel ball in the groove to the left of the leftmost magnet. Let the ball go. If it is close enough to the magnet, it will start rolling by itself, and hit the magnet.  \n \n gauss rifle ready\nClick on image for larger view  \n \n When the gauss rifle fires, it will happen too fast to see. The ball on the right will shoot away from the gun, and hit the target with considerable force. Our one foot long version is designed so the speed is not enough to hurt someone, and you can use your hand or foot as a target.
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(m)\n\nMake a solar cell in your kitchen\n\nWe found this article on http://www.scitoys.com/scitoys/scitoys/echem/echem2.html \n\nIt was super, super, super cool, so we thank them for allowing us to post it at TheSolarPlan.com!  This is nifty!\n\nA solar cell is a device for converting energy from the sun into electricity. The high-efficiency solar cells you can buy at Radio Shack and other stores are made from highly processed silicon, and require huge factories, high temperatures, vacuum equipment, and lots of money. \n\nIf we are willing to sacrifice efficiency for the ability to make our own solar cells in the kitchen out of materials from the neighborhood hardware store, we can demonstrate a working solar cell in about an hour. \n \nOur solar cell is made from cuprous oxide instead of silicon. Cuprous oxide is one of the first materials known to display the photoelectric effect, in which light causes electricity to flow in a material. \n\nThinking about how to explain the photoelectric effect is what led Albert Einstein to the Nobel prize for physics, and to the theory of relativity.\n\nMaterials you will need \n\nThe solar cell is made from these materials: \nA sheet of copper flashing from the hardware store. This normally costs about $5.00 per square foot. We will need about half a square foot. \nTwo alligator clip leads. \nA sensitive micro-ammeter that can read currents between 10 and 50 microamperes. Radio Shack sells small LCD multimeters that will do, but I used a small surplus meter with a needle. \nAn electric stove. My kitchen stove is gas, so I bought a small one-burner electric hotplate for about $25. The little 700 watt burners probably won't work -- mine is 1100 watts, so the burner gets red hot. \nA large clear plastic bottle off of which you can cut the top. I used a 2 liter spring water bottle. A large mouth glass jar will also work. \nTable salt. We will want a couple tablespoons of salt. \nTap water. \nSand paper or a wire brush on an electric drill. \nSheet metal shears for cutting the copper sheet. \n\n\n\n\n\n\nHow to build the solar cell \n\nMy burner looks like this: \n\nThe first step is to cut a piece of the copper sheeting that is about the size of the burner on the stove. Wash your hands so they don't have any grease or oil on them. Then wash the copper sheet with soap or cleanser to get any oil or grease off of it. Use the sandpaper or wire brush to thoroughly clean the copper sheeting, so that any sulphide or other light corrosion is removed. \n\nNext, place the cleaned and dried copper sheet on the burner and turn the burner to its highest setting. \n\nAs the copper starts to heat up, you will see beautiful oxidation patterns begin to form. Oranges, purples, and reds will cover the copper. \n\n\nAs the copper gets hotter, the colors are replaced with a black coating of cupric oxide. This is not the oxide we want, but it will flake off later, showing the reds, oranges, pinks, and purples of the cuprous oxide layer underneath. \n\n\n\nThe last bits of color disappear as the burner starts to glow red. \n\nWhen the burner is glowing red-hot, the sheet of copper will be coated with a black cupric oxide coat. Let it cook for a half an hour, so the black coating will be thick. This is important, since a thick coating will flake off nicely, while a thin coat will stay stuck to the copper. \n\n\nAfter the half hour of cooking, turn off the burner. Leave the hot copper on the burner to cool slowly. If you cool it too quickly, the black oxide will stay stuck to the copper. \n\nAs the copper cools, it shrinks. The black cupric oxide also shrinks. But they shrink at different rates, which makes the black cupric oxide flake off. \n\n\nThe little black flakes pop off the copper with enough force to make them fly a few inches. This means a little more cleaning effort around the stove, but it is fun to watch. \n\n\nWhen the copper has cooled to room temperature (this takes about 20 minutes), most of
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What equipment?\nWhat experiment?\nWhat error?
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The electron as a unit of charge in electrochemistry was posited by G. Johnstone Stoney in 1874, who also coined usage of "electron" in 1894. During the late 1890s a number of physicists posited that electricity could be conceived of as being made of discrete units, which were given a variety of names, but their reality had not been confirmed in a compelling way.\n\nThe discovery that the electron was a subatomic particle was made in 1897 by J.J. Thomson at the Cavendish Laboratory at Cambridge University, while he was studying "cathode rays". Influenced by the work of James Clerk Maxwell, and the discovery of the X-ray, he deduced that cathode rays existed and were negatively charged "particles", which he called "corpuscles." He published his discovery in 1897.\n\nThe periodic law states that the chemical properties of elements largely repeat themselves periodically and is the foundation of the periodic table of elements. The law itself was initially explained by the atomic mass of the elements. However, as there were anomalies in the periodic table, efforts were made to find a better explanation for it. In 1913, Henry Moseley introduced the concept of the atomic number and explained the periodic law with the number of protons each element has. In the same year, Niels Bohr showed that electrons are the actual foundation of the table. In 1916, Gilbert Newton Lewis explained the chemical bonding of elements by electronic interactions.
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well, a couple i can think of:\n\n- NMR (which, from looking at your gyromagnetic ratio question, i suspect is your thing, so i wont explain it)\n- hyperfine structure of spectral lines (comes from the coupling of nuclear to electronic spins)\n- you can also stick 'em in the path of a highly accelerated particle beam and measure the scattering as a function of azimuthal angle.  when i worked at SLAC we ran an experiment that did just this.\n\nthat's all i can come up with off the top of my head!
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Mendeleev table or somethgin linke that.  He formulated it in it's basic setup