Sodium doublet

Occasionally, typical pattern can be observed which can be formed according to special rules like multiplets in ESR-, NMR-, and OES spectroscopy or isotopic ratios in MS (molecular peak pattern). There can also be randomly formed pattern within such spectra, being rich in signals like OES (e.g. the known sodium doublet (Na-D) 589.6 and 589.0 nm, and the magnesium quintet 277.67, 277.83, 277.98, 278.14, and 278.30 nm). The identification of species is always made easier when pattern - whatever type - can be compared instead of a number of signals that are irregularly arranged. 

An intense emission line at 5900 A was believed to be the unresolved sodium doublet (5890 and 58% A). The appearance of sodium emission spectra is probably related to the presence of this element in the glass bottom. 

In the case of sodium atoms two slightly different energy levels exist in the excited state and two slightly different absorption wavelengths are observed, at 589 nm and 589.5 nm. These wavelengths coincide exactly with the yellow sodium doublet emission lines observed when sodium atoms are heated. 

Color plate 1 7 The solar spectrum, (a) Expanded color version of the solar spectrum shown in black and white in Feature 24-1 (Figure 24F-1). The huge number of dark absorption lines are produced by all of the elements in the sun. See if you can spot some prominent lines like the famous sodium doublet. 

Figure 24.13 Anomalous Zeeman splitting of the sodium doublet, (a) is split into four lines (b) D into six. (From Atomic Spectra and Atomic Structure by G. Herzberg, 1944, Dover Publications, Inc. N.Y.)...

A sodium solution is analyzed by flame emission using the S89-nm sodium-doublet... 

Developments also occurred during this time with respect to improvements in the determination of the wavelengths of spectral lines. Rowland s tables provided new wavelength measurements from the spectrum of the sun. He based his measurements on a weighted average for the sodium line, the longer wavelength line of the sodium doublet. 

It is important to evaluate the surface distortion associated with the assymetric field at the surface, a difficult task often simplified by assuming that distortion is limited to the direction normal to the plane [64, 6S]. Benson and co-workers [6S] calculated displacements for the first five planes in the (100) face of sodium chloride and found the distortion correction to of about 100 ergs/cm or about half of itself The displacements show a tendency toward ion pair formation, suggesting that lateral displacements to produce ion doublets should be considered [66] however, other calculations yielded much smaller displacements [67]. 

A careful investigation of this feature suggests that it is attributable to N02 associated with both Bronsted acid and M+ cations [29]. The doublet at 1400 cm is identical in position and appearance to that observed in a sample of Na-Y doped with NaNOs [30]. We therefore assign this peak to a NO3- species affiliated with the residual sodium in the catalyst. The position of the band at 1528 cm- is very similar to that for nitrito species in Co-A and Co-Y [22, 23] and is, therefore, assigned to Co-ONO. The features at 1599, and 1574 cm- are best assigned to C0-O2NO [30]. The band at 1633 cm- is similar to that observed on H-, Na-, and Cu-ZSM-5. We believe that this feature is best assigned to nitrito (NO2) or nitrate (NO3-) species. 

The resulting doublet sodium atom can then emit light at the sodium TMiric at 589 nm. With so many steps requiring atomic sodium, its concentration, which increases with temperature, significantly affects the chemiluminescent yield. Therefore, the temperature of the solid sodium must be tightly controlled. The excited sodium halide is readily quenched by ambient air molecules, so the system works best at reduced pressure. 

D line spect The yellow line that is the first line of the major series of the sodium spectrum the doublet in the Fraunhofer lines whose almost equal components have wavelengths of 5895.93 and 5889.96 angstroms respectively. de, lTn ... 

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