Lithium line spectrum

There is more good news. Anyone who has stared at the periodic table and has taken basic chemistry knows that the orbital structure postulated for atoms is the same for all kinds of atoms. And all atoms exhibit a line spectrum that is independent of the viewer s position. So there is no reason, in principle, why you couldn t solve this problem for other sorts of atoms too. The basic ideas are indeed the same. Of course, problems arise in interpretation. For example, if we are interpreting our little electron as a wave, then what are we supposed to do with two electrons After all, a wave plus a wave is still just a wave. As near as I can tell, quantum mechanics still has a way to go before it replaces the old fashioned pictures of helium, lithium and other, more complex, atoms. And any physicist can tell you that molecules, stripped of their pretty spherical symmetry, are trouble indeed. 

Each element has a characteristic line spectrum that can be used to identify the element. Note that line emission spectra can also be obtained by heating a salt of a metal with a flame. For instance, common salt (sodium chloride) provides a strong yellow light to the flame coming from excited sodium, while copper salts emit a blue-green light and lithium salts a red light. The colors of fireworks are due to this phenomenon. 

Raman spectra are usually represented by the intensity of Stokes lines versus the shifted frequencies 12,. Figure 1.15 shows, as an example, the Raman spectrum of a lithium niobate (LiNbOs) crystal. The energies (given in wavenumber units, cm ) of the different phonons involved are indicated above the corresponding peaks. Particular emphasis will be given to those of higher energy, called effective phonons (883 cm for lithium niobate), as they actively participate in the nonradiative de-excitation processes of trivalent rare earth ions in crystals (see Section 6.3). 

Many elements are present in the earth s crust in such minute amounts that they could never have been discovered by ordinary methods of mineral analysis. In 1859, however, Kirchhoff and Bunsen invented the spectroscope, an optical instrument consisting of a collimator, or metal tube fitted at one end with a lens and closed at the other except for a slit, at the focus of the lens, to admit light from the incandescent substance to be examined, a turntable containing a prism mounted to receive and separate the parallel rays from the lens and a telescope to observe the spectrum produced by the prism. With this instrument they soon discovered two new metals, cesium and rubidium, which they classified with sodium and potassium, which had been previously discovered by Davy, and lithium, which was added to the list of elements by Arfwedson. The spectroscopic discovery of thallium by Sir William Crookes and its prompt confirmation by C.-A. Lamy soon followed. In 1863 F. Reich and H. T. Richter of the Freiberg School of Mines discovered a very rare element in zmc blende, and named it indium because of its brilliant line in the indigo region of the spectrum. 

Fox Talbot (24), an English scientist, found in 1834 that, with the aid of a prism, he could distinguish lithium from strontium, even though the salts of both give red flames (4, 26, 32). He stated that the dark lines previously observed by Sir David Brewster (33) in the spectrum of light which had passed through vapors of nitrous acid were caused by absorption of light (5,25). 

W. N. Hartley 57 found the alkali chlorides in the oxyhydrogen blowpipe flame give lines of elements with a more or less continuous spectrum believed to be due to the respective metals. Lithium chloride, however, gives no continuous spectrum. G. P. Thomson studied the anode rays from lithium chloride and other alkali halides. 

The Selection Rule for L - The energy-level diagram for lithium as. shown in Figure 2-6 has been obtained by analysis of the spectrum of the lithium atom. Lines are observed in the spectrum of lithium corresponding to the transition from one of the states indicated in the diagram to another state. The lines that are observed in the spectrum do not represent all combinations of the energy levels, however, but... 

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