Lyman

Bafmer series Frequencies of certain lines in the spectrum of hydrogen are simply related to each other, and can be expressed by a general formula. One group of lines is termed the Balmer series. Other series were later discovered in the spectrum of hydrogen by Lyman, Paschen, Brackett and Pfund. 

Lyman series See Balmer series, lyogels See xerogels. 

Procedure. Use Mathcad, QLLSQ, or TableCurve (or, preferably, all three) to determine a value of the ionization energy of hydrogen from the wave numbers in Table 3-4 taken from spectroscopic studies of the Lyman series of the hydrogen spectrum where ni = 1. 

Table 3-4 Spectral Wavenumbers v for the Lyman Series of Hydrogen...

W. J. Lyman, W. F. Reehl, D. H. Rosenblatt, Handbook of Chemical Property Estimation Methods American Chemical Society, Washington (1990). 

Figure 1.1 Energy levels (vertical lines) and observed transitions (horizontal lines) of the hydrogen atom, including the Lyman, Balmer, Paschen, Brackett and Pfund series...

Comparison with the empirical Equation (1.4) shows that = /re /S/z eg and that n" = 2 for the Balmer series. Similarly n" = 1, 3, 4, and 5 for the Lyman, Paschen, Brackett and Pfimd series, although it is important to realize that there is an infinite number of series. Many series with high n" have been observed, by techniques of radioastronomy, in the interstellar medium, where there is a large amount of atomic hydrogen. For example, the (n = 167) — ( " = 166) transition has been observed with V = 1.425 GFIz (1 = 21.04 cm). 

Far-ultraviolet Microwave discharge in noble gases Lyman discharge LiF (or no windows) Grating Photomultiplier photodiode photographic plate... 

It is possible to change the conditions in the helium discharge lamp so that the helium is ionized predominantly to He (He II). The radiation is due mainly to the n = 2 — n = transition of He II (analogous to the first member of the Lyman series of the hydrogen atom in Figure 1.1) at 30.4 nm with an energy of 40.81 cY A thin aluminium foil filter can be used to remove any He I radiation. 

T. Lyman and co-eds.. Metals Handbook, 8th ed., Vol. 1, American Society for Metals, Metals Park, Ohio, 1976, p. 864. 

Various methods are available for estimation of the normal boiling point of organic compounds. Lyman et al. review and give calcula-tional procedures for the methods of Meissner, Miller, and Lydersen/ Forman-Thodos. A more recent method that has been determined to be more accurate is the method of Pailhes, which reqmres one experimental vapor pressure point and Lydersen group contributions for critical temperature and critical pressure (Table 2-385). 

The dipole moment (A) of a molecule is the first moment of the elec tric charge density of a molecule. Paraffins have dipole moments of zero, while dipole moments of almost all hydrocarbons are small. McClellan lists many dipole moments. The computer method of Dixon and Jurs" is the most useful method for predicting dipole moments. Lyman et al. give other methods of calculation. 

Scheel, Lyman F., Gas Machinery, Homston, TX Gulf Publishing Company, 1972. 

Scheel, Lyman F Gas Machinery, Houston, TX Gulf Publishing Compa-nv, 1972. 

C. E. Lyman, H. G. Stenger, and J. R. Michael. Ultramicroscopy 22, 129, 1987. This paper demonstrates high-resolution compositional imaging with the field-emission STEM. 

Dr. Warren Lyman 1 Center Plaza Boston, MA 02108 (617) 742-5151 x5711... 

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