Sodium vapor

Niobium is used as a substrate for platinum in impressed-current cathodic protection anodes because of its high anodic breakdown potential (100 V in seawater), good mechanical properties, good electrical conductivity, and the formation of an adherent passive oxide film when it is anodized. Other uses for niobium metal are in vacuum tubes, high pressure sodium vapor lamps, and in the manufacture of catalysts. 

Metals do not generally react with vitreous siUca below 1000°C or their melting point, whichever is lower. Exceptions are alurninum, magnesium, and alkah metals. Aluminum readily reduces siUca at 700—800°C. Alkali metal vapors attack at temperatures as low as 200°C. Sodium vapor attack involves a diffusion of sodium into the glass, followed by a reduction of the siUca. 

Sodium vapor lamps, in use for many years, continue to be improved, both with respect to efficiency and color of emitted light. These lamps, however, contain only a few milligrams of sodium each. 

Bromine reacts with essentially all metals, except tantalum and niobium, although elevated temperatures are sometimes required, eg, soHd sodium does not react with dry bromine but sodium vapor reacts vigorously. Metals such as lead, magnesium, nickel, and silver react with bromine to form a surface coat of bromide that resists further attack. This protective coating allows lead and nickel to be used as linings in bromine containers. Metals tend to be corroded by bromine faster in the presence of moisture than without, probably because of the formation of hydrobromic and hypobromous acids. 

HID fixtures include those using mercury vapor and sodium vapor lamps. Mercury vapor fixtures are usually less expensive than sodium... 

Fireworks displays are fascinating to watch. Neon lights and sodium vapor lamps can transform the skyline of a city with their brilliant colors. The eerie phenomenon of the aurora borealis is an unforgettable experience when you see it for the first time. All of these events relate to the generation of light and its transmission through space. 

Sodium vapor lamps are commonly used to illuminate highways because of their intense yellow-orange emissions at 589 nm. 

Sodium bicarbonate, 112-113 Sodium carbonate, 61 Sodium chloride 44q common ion effect and, 439 electrolysis, 499 formation, 3 structure, 36 Sodium chlorine, 4 Sodium hydroxide, 61,84,441 Sodium hypochlorite, 369-370 Sodium stearate, 595 Sodium vapor lamps, 135 Solids... 

The reduction of K2TaF7 can also be performed using sodium vapors [584]. This process is conducted at an Na pressure as low as 0.1 torr, which enables the removal of interferring gases such as N, O and H20. The interaction begins at 350°C. The temperature further increases up to 800°C to prevent the condensation of sodium and the formation of colloidal tantalum powder. The product of the interaction is removed from the reactor after cooling and treated with boiled HC1 and HF solutions. The method enables the production of coarse grain tantalum powder with 99.5% purity. 

Sodium vapor lamps, used for public lighting, emit yellow light of wavelength 589 nm. How much energy is emitted by... 

The alkali metals are the most violently reactive of all the metals. They are too easily oxidized to be found in the free state in nature and cannot be extracted from their compounds by ordinary chemical reducing agents. The pure metals are obtained by electrolysis of their molten salts, as in the electrolytic Downs process (Section 12.13) or, in the case of potassium, by exposing molten potassium chloride to sodium vapor ... 

A sodium-vapor street lamp emits yellow light at wavelength A — 589 nm. What is the energy change for a sodium atom involved in this emission How much energy is released per mole of sodium atoms ... 

Sodium vapor lamps emit yellow light. 

Excited-state configurations are perfectiy vaiid as iong as they meet the restrictions given in Table. In the electrical discharge of a sodium vapor lamp, for instance, we find some sodium atoms in excited states with configurations such as 2 2 3 p or 2 2 p 3 These configurations use valid orbitals a... 

These equations illustrate how the crystal responds to the presence of sodium vapor, i.e.- excess Na- -, by forming anion vacaneies, to form the F-center. 

C by external cooling. During this process a part of the reduction occurs between titanium tetrachloride and sodium vapor and this leads to the formation of titanium powder. To avoid this, the reduction is carried out in two steps. Initially, stoichiometric amounts of sodium and titanium tetrachloride are metered into the steel retort at 700 to 750 °C to produce titanium dichloride ... 

Figure 13. The production of negative ions by charge exchange in sodium vapor for a variety of ion species and exchange energies.

SODIUM VAPOR, VITREOUS SILICA REACTION WITH... 

Sodium vapor, vitreous silica reaction with, 22 418... 

Another common use is as a liquid contact in electrical silent switches. Also, mercury-vapor produces the bluish-white light of streedights. However, mercury-vapor hghts now are being replaced by sodium-vapor lights that produce a yellowish-white hght. Mercury is used in thermometers and barometers, to coat mirrors, and in the electronics industry and several other industries. 

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