franck-hertz error analysic Ringold Oklahoma

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franck-hertz error analysic Ringold, Oklahoma

The velocity for a charged particle in motion can then be solved for: And so the kinetic energy of this particle would be: Bohr assumed the electrons moved in a circular This experiment is of enormous historical importance because it provided experimental data that confirmed Bohrís model of the atom, and the data was also in agreement with spectroscopic results. The tube is provided with a highly activated contact getter and is exhausted to a high vacuum. Choose a value for this parameter so that the chi square difference between the data points and the spline is approximately equal to the number of data points N, give or

You will need to compute and write out chi square to monitor this criterion. At the point of the third collision, the accelerating potential is very high. It correctly predicts the hydrogen spectrum, but only lends itself qualitatively to atoms with more than one electron. Theory:

In order to understand the processes involved in this experiment, some knowledge of the structure of atoms is needed.

This was investigated using thermionically emitted electrons that were subsequently accelerated by a variable potential through a monatomic vapor. The valleys could not be used because there were only two equally spaced valleys, with a small third valley appearing very near the end of the graph. You will need to figure out how to use this code. Generated Sat, 15 Oct 2016 23:30:51 GMT by s_wx1094 (squid/3.5.20) ERROR The requested URL could not be retrieved The following error was encountered while trying to retrieve the URL: http://0.0.0.10/ Connection

Note that there are six maxima near x = 11, 16, 21, 26, 31, and 36. Hanne, G.F., 1988, Am. Circular motion can be described as: Where F is the centripetal force acting on the object that is rotating, m is the mass of the object, v is the tangential component Your cache administrator is webmaster.

This incorporates the standard deviation of points from the mean. Melissinos, Adrian C., Experiments in Modern Physics, Academic Press Inc., New York, 1966, pg 8. Franck and G. The values obtained by this method are: Data Conditions Excitation Energy (Electron-Volts) Uncertainty Mercury (150° C) peak 5.195466 0.515465 Mercury (180° C) peak 4.864026 0.718293 Mercury (150° C) valley 5.159764 0.747322

If you choose the discrete spline step size parameter $h$ to be much smaller than the interval between the x values, you will get better continuity of the first derivative, which This could ultimately change the distance between peaks if more than one energy transition were occurring. Other general errors not associated with a particular set of data, but rather all of Neon:

The apparatus consists of a neon-filled Franck-Hertz tube in a housing; a control unit with power supplies, reverse voltage source and DC preamplifier; and a shielded cable with BNC connector. Approximately 3-5 peaks (or valleys) were obtained from each graph (Peak Energy v.s.

This would not be a terrible result if it were truly what was being observed. This is achieved I believe, for the most part, because this method incorporates a larger uncertainty into each value. Another effect that could have influenced the data is that of the value of the contact potential difference. Rohlf, James W., Modern Physics: from a to Z0, John Wiley & Sons, 1994.

The system returned: (22) Invalid argument The remote host or network may be down. The concept of quantization of energy in matter originates in these two propositions, and is realized in the following derivation. This method takes into account the uncertainty in each point, and places less emphasis on those points which have a higher uncertainty. Works Cited Brehm, J.J., and W.J.

The electrodes are placed in parallel planes. First, the electrons in the atom may exist in a discrete set of stationary states of definite energy, defined so that radiation is not emitted continuously. Second, the atom may undergo a non-classical transition from one of these allowed states to another and thereby emit or absorb a single quantum of electromagnetic radiation. This formula is not exactly correct, but its historic significance is great in that it laid a large portion of groundwork for the new quantum theory.

Thus, it should be noted that the energy spacing between peaks at the 150° Celsius temperature (which has a lower vapor pressure than the 180° Celsius data) which corresponded to a This second energy valley (second part of the third valley) is a result of the electrons acquiring the excitation energy further away from the collector anode, and therefore, the current begins I could probably be a little more bold in my assertions, but the data I obtained is very good, and assumes nothing. Sample: Data # Current Accelerating Voltage 1 .12 4.64 2 .12 4.67 3 .13 4.72 4 .15 4.87 5 (Peak) .16 4.90 6 (Peak) .16 4.94 7 .15 4.95 8 .11

Since the accelerating potential is so high, even though the electrons lose their kinetic energy, the electrons in a sense arc over the last potential hump. The emitted electrons form a sheath of negative charge in the vicinity of the cathode, and inhibit further emission. I suggest you search the netlib site . The mercury data at 180° Celsius seemed to correlate exactly to a 4.89 eV energy transition, which is the conventionally expected energy transition in this experiment.

The quantization condition that Bohr placed on angular momentum was: This expression was somewhat of a guess that Bohr arrived at in light of the latest observations, namely that Planck had These decreases in current always occurred with the same spacing, which can be interpreted as the electrons transferring only discrete amounts of energy to the atoms, and this energy corresponds to These can be used to construct the spline curve and find the maxima you need. Either there existed a systematic error that incessantly gave lower values for the spacing between peaks, or somehow only a small number of electrons were reaching the 2p53p3 S1 (18.3 eV)

Generated Sat, 15 Oct 2016 23:30:51 GMT by s_wx1094 (squid/3.5.20) ERROR The requested URL could not be retrieved The following error was encountered while trying to retrieve the URL: http://0.0.0.5/ Connection As the accelerating potential approaches a very large value (i.e. There is also a statistical error associated with uncertainties in the current measurement. This was due to the electrons colliding inelastically with the atoms in the tube. (Note: the reason for the ~ 7eV and ~ 20eV instead of the ~ 5eV and ~

However, if an electron manages to excite a mercury atom, it must lose 4.9 eV of energy in the process. The electrons are ejected with little or no kinetic energy, and are subsequently accelerated from rest by a variable potential. The apparatus consists of a three-electrode tube as illustrated in the schematic. Today it is a favorite experiment for undergraduate physics laboratories.

This is good because the bad value (~5.7 eV) was a result of the fact that the peak values fluctuated. The data however is somewhat misleading in the sense that the peaks of the mercury graph at 150° Celsius were very chaotic (see graph on next page). The other explanation given talks in detail about the formation of temporarily negative ion states, however this is far beyond the scope of this paper. If the accelerating potential was changed too rapidly however, then the valley would have a very sharp minimum.

The tube contains mercury vapor at low pressure. One error that could have a small effect on the peak spacing is the distribution of velocities that accompanies thermionic emission. Space charge is cause by electrons that are ejected thermionically from a metal. There were two results obtained for mercury.

The accelerating voltage V is varied from 0 to 70 V. This is not altogether unfeasible, but I will show that it is unlikely.