Sodium emission spectrum

Fig. 3.1.4 Bioluminescence spectrum of Cypridina luciferin catalyzed by Cypridina luciferase (A), the fluorescence excitation spectrum of oxyluciferin in the presence of luciferase (B), the fluorescence emission spectrum of the same solution as B (C), and the absorption spectrum of oxyluciferin (D). The fluorescence of oxyluciferin alone and luciferase alone are negligibly weak. Measurement conditions A, luciferin (lpg/ml) plus a trace amount of luciferase in 20 mM sodium phosphate buffer, pH 7.2, containing 0.2 M NaCl B and C, oxyluciferin (20 pM) plus luciferase (0.2mg/ml) in 20 mM sodium phosphate buffer, pH 7.2, containing 0.2 M NaCl D, oxyluciferin (41 pM) in 20 mM Tris-HCl buffer, pH 7.6, containing 0.2 M NaCl. All are at 20°C.

Table 12.1. The wavelengths of the major spectral lines (nm) in the emission spectrum of sodium, arranged in series which are analogous to those in hydrogen.

Figure 12.7 Electronic transitions giving rise to the emission spectrum of sodium in the visible, as listed in Table 12.1. The principal series consists of transitions from the 3s level to 3p or a higher p orbital the sharp series from 3p to 4s or a higher s orbital diffuse from 3p to 3d or above and the fundamental from 3d to 4/or higher. The terms below the lines [(R/(3-1.37)2, etc.] are the quantum defect corrections referred to in Section 10.4.

In the specific case of sodium the resulting emission spectrum shall exhibit characteristic yellow lines. The spectrum is so highly sensitive that even the traces of Na show yellow lines distinctly. 

Spectroscopy is the study of the absorption and emission of radiation by matter. The most easily appreciated aspect of the absorption of radiation is the colour shown by substances that absorb radiation from the visible region of the spectrum. If radiation is absorbed from the red region of the spectrum, the transmitted or unabsorbed radiation will be from the blue region and the substance will show a blue colour. Similarly substances that emit radiation show a particular colour if the radiation is in the visible region of the spectrum. Sodium lamps, for instance, owe their characteristic orange-yellow light to the specific emission of sodium atoms at a wavelength of 589 nm. 

The high resolution emission spectrum of sodium suggests that shells are subdivided into subshells. Using quantum mechanics, it can be calculated that all shells have at least one subshell. 

The yellow flame colour is due to atomic emission from sodium where the spectrum is dominated by a broad emission centred on 590 nm (the resonance transition is that from the ground state to the lowest energy excited state in absorption and the reverse will apply in emission). 

Yellow flame color is achieved by atomic emission from sodium. The emission intensity at 589 nanometers increases as the reaction temperature is raised there is no molecular emitting species here to decompose. Ionization of sodium atoms to sodium ions will occur at very high temperatures, however, so even here there is an upper limit of temperature that must be avoided for maximum color quality. The emission spectrum of a yellow flare is shown in Figure 7.2. 

Electronic transitions within a sodium atom giving rise to the main bands in its emission spectrum. 

Fig. 17 Ratio of third to first vibrational peak of pyrene emission spectrum as a function of DTAB concentration in the presence of 1 g/L sodium polyacrylate...

T. Melville noted in 1752 that sodium colours the flame of alcohol yellow, and A. S. Marggraf used this as a test to distinguish sodium from potassium salts. With an ordinary one-prism spectroscope, the spectrum appears with a single yellow fine corresponding with the D-line of the solar spectrum. This line really consists of two lines of wave-length 5896 and 5890. The emission spectrum of sodium shows many other lines of feeble intensity. In a salted Bunsen s flame, practically... 

In the same way, the sodium atoms can be promoted to the doublet levels 3 2Py2 or 3 2Ptii which are split due to spin-orbit coupling. When such atoms return to the ground state, the two closely spaced lines are observed in the emission spectrum. These are the well known D lines of sodium (Figure 2.5). 

The laser atomic fluorescence excitation and emission spectra of sodium in an air-acetylene flame are shown below. In the excitation spectrum, the laser (bandwidth = 0.03 nm) was scanned through various wavelengths while the detector monochromator (bandwidth = 1.6 nm) was held fixed near 589 nm. In the emission spectrum, the laser was fixed at 589.0 nm, and the detector monochromator wavelength was varied. Explain why the emission spectrum gives one broad band, whereas the excitation spectrum gives two sharp lines. How can the excitation linewidths be much narrower than the detector monochromator bandwidth ... 

Fluorescence excitation and emission spectra of the two sodium D lines in an air-acetylene flame, (a) In the excitation spectrum, the laser was scanned, (to) In the emission spectrum, the monochromator was scanned. The monochromator slit width was the same for both spectra. [From s. J. Weeks, H. Haraguchl, and J. D. Wlnefordner, Improvement of Detection Limits in Laser-Excited Atomic Fluorescence Flame Spectrometry," Anal. Chem. 1976t 50,360.]... 

Figure 3. Variation in the Eu emission spectrum for [Eu.2c] (pH 7.4, 0.1M MOPS) following incremental addition of sodium hydrogencarbonate spectra in the insets show formation of isoemissive points at 588 and 702 nm.

Sodium salts, when heated in a flame, give that flame a bright yellow color, and this color matches the two brightest lines in the emission spectrum of sodium. Sodium is found widely in nature, and lots of substances produce these lines. Fraunhofer had found that the spectrum of a candle flame contained two bright lines precisely corresponding to two dark lines, known as the D lines, in the emission spectrum of the sun. 

One of the most successful techniques of detecting small amounts (say 10-9 to 10 6g) of uranium is the fluorescence after incorporation in molten sodium fluoride22,181). Since the light emitted is green, and since the emission spectrum shows some vibrational structure, it was the general opinion before 1956 that some kind of imbedded uranyl... 

The emission spectra for uranyl-exchanged zeolites Y, mordenite and X all have differences but do show some fine structure and therefore resemble the solid state spectrum of uranyl acetate dihydrate. In fact, the spectrum of uranyl ions exchanged into sodium mordenite is very similar to that of the uranyl acetate dihydrate solid spectrum shown in Figure 1. Further support for our belief that some zeolites have a solution like environment and others have a solid like environment comes from the correlation between the crystallinity of these uranyl-exchanged zeolites and the appearance of some fine structure in the emission spectrum. We find no apparent correlation between this fine structure and the concentration of the uranyl ion in the zeolites even with a ten-fold change in the concentration of the uranyl ion. 

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