Davy, Humphry sodium

The M-NM transition has been a topic of interest from the days of Sir Humphry Davy when sodium and potassium were discovered till then only high-density elements such as Au, Ag and Cu with lustre and other related properties were known to be metallic. A variety of materials exhibit a transition from the nonmetallic to the metallic state because of a change in crystal structure, composition, temperature or pressure. While the majority of elements in nature are metallic, some of the elements which are ordinarily nonmetals become metallic on application of pressure or on melting accordingly, silicon is metallic in the liquid state and nonmetallic in the solid state. Metals such as Cs and Hg become nonmetallic when expanded to low densities at high temperatures. Solutions of alkali metals in liquid ammonia become metallic when the concentration of the alkali metal is sufficiently high. Alkali metal tungsten bronzes... 

Sir Humphry Davy isolates sodium by the electrolysis of caustic soda (NaOH) and names the metal. /... 

Because of their metallic and alkaline properties, potassium and especially sodium are widely used in a variety of industrial processes both as metals and as compounds with various other elements. Lithium is rarely used, but does find application in lightweight alloys with magnesium. Rubidium and cesium are not commonly utilized industrially, except for some applications in electronics. Sodium and potassium are essential for life, sodium being the principal extracellular and potassium the major intracellular monovalent cations. The other alkali metals have no essential biological role, see ALSO Bunsen, Robert Cesium Davy, Humphry Francium Lithium Mendeleev, Dimitri Potassium Rubidium Sodium. 

Sodium borohydride is marketed in powdered or pellet form, and in solution, for use in fuel cells. Boron nitride can withstand temperatures of up to 650°C (1,202°E) when subjected to high pressures and temperatures, it forms cubic crystals whose hardness rivals that of diamond. Boron carbide, produced by reacting coke and boric acid at 2,600°C (4,712°E), is a highly refractory material and one of the hardest substances known. It has both abrasive and abrasion-resistant applications, and is used in nuclear shielding, see ALSO Davy, Humphry Gay-Lussac, Joseph-Louis Nuclear Chemistry. 

Sir Humphry Davy first isolated metallic sodium ia 1807 by the electrolytic decomposition of sodium hydroxide. Later, the metal was produced experimentally by thermal reduction of the hydroxide with iron. In 1855, commercial production was started usiag the DeviUe process, ia which sodium carbonate was reduced with carbon at 1100°C. In 1886 a process for the thermal reduction of sodium hydroxide with carbon was developed. Later sodium was made on a commercial scale by the electrolysis of sodium hydroxide (1,2). The process for the electrolytic decomposition of fused sodium chloride, patented ia 1924 (2,3), has been the preferred process siace iastallation of the first electrolysis cells at Niagara Falls ia 1925. Sodium chloride decomposition is widely used throughout the world (see Sodium compounds). 

The spectacular success (in 1807) of Humphry Davy, then aged 29 y, in isolating metallic potassium by electrolysis of molten caustic potash (KOH) is too well known to need repeating in detail." Globules of molten sodium were similarly prepared by him a few days later from molten caustic soda. Earlier experiments with aqueous solutions had been unsuccessful because of the great reactivity of these new elements. The names chosen by Davy reflect the sources of the elements. 

Boron (Buraq in Arabic/Burah in Persian, which is the word for white, the color being attributed to borax (sodium tetraborate, Na2B4O7.10H2O)) was discovered in 1808 independently by the British Chemist, Sir Humphry Davy, and two French chemists, Joseph Louis Gay-Lussac and Loius Jacques Thenard.1 They isolated boron in 50% purity by the reduction of boric acid with sodium or magnesium. The Swedish chemist Jons Jakob Berzilius identified boron as an element in 1824. The first pine sample of boron was produced by the American chemist William Weintraub in 1909. Boron does not appear in nature in elemental form, but is found in its compounded... 

Sodium (Na, [Ne s1), name from the English word soda, perhaps from the Latin word sodanum (glasswort), symbol from the Latin natrium (sodium carbonate). Identified and isolated (1807) by Sir Humphry Davy. 

The electrolysis of aqueous solutions may not yield the desired products. Sir Humphry Davy (1778-1829) discovered the elements sodium and potassium by electrolyzing their molten salts. Before this discovery, Davy had electrolyzed aqueous solutions of sodium and potassium salts. He had not succeeded in reducing the metal ions to the pure metals at the cathode. Instead, his first experiments had produced hydrogen gas. Where did the hydrogen gas come from ... 

Sodium - the atomic number is 11 and the chemical symbol is Na. The name derives from the English soda and Latin sodanum for headache remedy . The chemical symbol Na derives from the Latin natrium for natron (soda in english) . It was discovered in 1807 by the English chemist Humphry Davy from electrolyosis of caustic soda (NaOH). 

In 1807 Sir Humphry Davy (1778-1829) devised an electrolysis apparatus that used electrodes immersed in a bath of melted sodium hydroxide. When he passed an electric current through the system, metallic sodium formed at the negative (cathode) electrode. He first performed this experiment with molten potassium carbonate to liberate the metal potassium, and he soon followed up with the sodium experiment. Today, sodium and some of the other alkali metals are still produced by electrolysis. The types of electrolytes may vary using a mixture of sodium chloride and calcium chloride and then further purifying the sodium metal. 

By the early 1800s several chemists had separated potassium and sodium as elements from compounds. It was believed that metallic calcium could be obtained by similar methods. In 1808 Sir Humphry Davy finally produced the metallic element calcium from a mixture of lime and mercuric oxide by his experimental electrolysis apparatus. This was the same process he had previously used to discover several other alkali earth metals. 

Similar to the history of many other elements, iodine s discovery was serendipitous in the sense that no one was looking for it specifically. In 1811 Bernard Courtois (1777—1838), a French chemist, attempted to remove sodium and potassium compounds from the ash of burned seaweed in order to make gunpowder. After removing these chemicals from the ash, he added sulfuric acid (H SO j) to the remaining ash. However, he mistakenly added too much acid, which produced a violet-colored vapor cloud that erupted from the mixture. This violet vapor condensed on all the metallic objects in the room, leaving a layer of sohd black iodine crystals. Sir Humphry Davy (1778—1829) confirmed this discovery of a new element and named it iodine after the Greek word iodes, which means violet, but it was Courtois who was given credit for the discovery of iodine. 

Sodium Na 1807 (London, England) Sir Humphry Davy (British) 50... 

Sodium was first isolated by Sir Humphry Davy in 1807 by electrolysis of caustic soda. In the following year. Gay Lussac and Thenard obtained metallic sodium by chemical reduction of caustic soda with iron at elevated temperatures. Deville, in 1854, prepared the metal by reduction of sodium carbonate and lime with charcoal at a temperature above the boiling point of sodium. Castner, in 1886, improved the chemical reduction process preparing the metal by heating sodium hydroxide with iron carbide at high temperature. Five years later he patented a process based on electrolytic reduction of sodium hydroxide. The first major commercial plant was set up in 1921 with the introduction of Downs cell. 

Sir Humphry Davy, 1778—1829. English chemist and physicist. One of the founders of electrochemistry. Inventor of die safety lamp for miners. He was the first to isolate potassium, sodium, calcium, barium, strontium, and magnesium. Davy in England and Gay-Lussac and Thenard in France, working independently, were die first to isolate boron. 

Within a few years, more elements were found. With the help of electricity, an English chemist, Humphry Davy, in a single year brought to light six new metals — among them sodium, potassium, calcium, and magnesium. 

In 1807, the British scientist, Humphry Davy, succeeded in isolating the metals found in these salts. They proved to he wax-soft and silvery. He called them sodium (from soda ash) and potassium (from potash). These are still their English names. But in chemical formulas they are referred to as natrium (Na) and kalium (K) — from abbreviations of the Arabic names of the ashes nairun and al qili (alkali). 

In 1800. William Nicholson and Anthony Carlisle decomposed water into hydrogen and oxygen by an electric current supplied by a voltaic pile. Whereas Volta had pruduced electricity from chemical action these experimenters reversed the process and utilized electricity to produce chemical changes. In 1807. Sir Humphry Davy discovered two new elements, potassium and sodium, by the electrolysis of ihe respective solid hydroxides, utilizing a voltaic pile as the source of electric power. These electrolytic processes were the forerunners of the many industrial electrolytic processes used today to obtain aluminum, chlorine, hydrogen, or oxygen, for example, or in die electroplating of metals such as silver or chromium. 

Metals high in the reactivity series have proved very difficult to isolate. It was not until more recent times, through Sir Humphry Davy s work on electrolysis, that potassium (1807), sodium (1807), calcium (1808) and magnesium (1808) were isolated. Aluminium, the most plentiful reactive metal in the Earth s crust, was not extracted from its ore until 1827, by Friedrich Wohler (p. 74), and the extremely reactive metal rubidium was not isolated until 1861 by Robert Bunsen and Gustav Kirchhoff. 

As early as 1969, Pedersen was intrigued by the intense blue colour observed upon dissolution of small quantities of sodium or potassium metal in coordinating organic solvents in the presence of crown ethers. Indeed, the history of alkali metal (as opposed to metal cation) solution chemistry may be traced back to an 1808 entry in the notebook of Sir Humphry Davy, concerning the blue or bronze colour of potassium-liquid ammonia solutions. This blue colour is attributed to the presence of a solvated form of free electrons. It is also observed upon dissolution of sodium metal in liquid ammonia, and is a useful reagent for dissolving metal reductions , such as the selective reduction of arenes to 1,4-dienes (Birch reduction). Alkali metal solutions in the presence of crown ethers and cryptands in etheric solvents are now used extensively in this context. The full characterisation of these intriguing materials had to wait until 1983, however, when the first X-ray crystal structure of an electride salt (a cation with an electron as the counter anion) was obtained by James L. Dye and... 

It is interesting to note that this process led, in the hands of Sir Humphry Davy, to the discovery of the metals of the alkalies, potassium and sodium he first prepared them by passing a current from a battery of high voltage... 

Potassium and sodium were first isolated within a few days of each other in 1807 by Humphry Davy as products of the electrolysis of molten KOH and NaOH. In 1817, J. A. Arfvedson, a young chemist working with J. J. Berzelius, recognized similarities between the solubilities of compounds of lithium and those of sodium and potassium. The following year, Davy also became the first to isolate lithium, this time by electrolysis of molten Li20. Cesium and rubidium were discovered with the help of the spectroscope in 1860 and 1861, respectively they were named after the colors of the most prominent emission lines (Latin, caesius, sky blue, rubidus, deep red). Francium was not identified until 1939 as a short-lived radioactive isotope from the nuclear decay of actinium. 

Barium was first isolated in 1808 by English chemist Sir Humphry Davy (1778-1829). In 1807 and 1808, Davy also discovered five other new elements sodium, potassium, strontium, calcium, and magnesium. All... 

In 1808, English chemist Humphry Davy (1778—1829) had just learned how to isolate the most active metals, such as sodium and potassium. He was also working on a method to remove boron from its compounds. 

Compounds of sodium have been known, of course, throughout human history. But sodium metal was not prepared until 1807. The reason is that sodium attaches itself very strongly to other elements. Its compounds are very difficult to break apart. It was not until 1807 that English chemist Sir Humphry Davy (1778—1829) found a way to extract sodium from its compounds. 

English chemist Sir Humphry Davy isolates a number of elements in a pure form for the first time, including potassium, sodium, magnesium, barium, calcium, and strontium. 

Sodium is such a reactive metal that preparing it through a chemical process can be dangerous. Sir Humphry Davy first isolated it in 1807 by the electrolysis of molten sodium hydroxide. Today, sodium is made by the electrolysis of molten sodium chloride in a Downs cell, as shown in Figure 17. 

The dual aspect of the electrochemical cell—galvanic or electrolytic—was recognized shortly after the cell s discovery in 1800 by Alessandro Volta. Volta constructed a battery of cells consisting of a number of plates of silver and zinc that were separated from one another by porous strips of paper saturated with a salt solution. By 1807, Sir Humphry Davy had prepared elemental sodium and potassium by using a battery to electrolyze their respective hydroxides. But, the underlying scientific basis of the electrochemical cell was not understood. Michael Faraday s research showed a direct quantitative relationship between the amounts of substances that react at the cathode and the anode and the total electric charge that passes through the cell. This observation is the substance of Faraday s laws, which we state as follows ... 

The English name sodium was created by Humphry Davy (1778-1829) because he isolated sodium metal from soda by electrolysis in 1807. Soda was a version of the medieval Latin sodanum, a name for a headache remedy, which in turn probably came from the Arabic Sudd (soda). Because of its similarity to... 

---