Flotte’s Outlines

 

Chemistry

 

 

 

History

·         1535 Sulfuric acid is prepared in Arabia

·         1662 Boyle describes the physical properties of gases

·         1700s Phlogiston was the name given to a hypothetical substance contained in flammable substances and given off (and depleted) during combustion. The theory was developed in the early 1700s by Georg Stahl.

·         1766 Henry Cavendish discovers hydrogen

·         1771 Carl Scheele discovers oxygen.

·         1772 Joseph Priestley and Daniel Rutherford independently discover nitrogen.

·         1775 Priestley discovers hydrochloric and sulfuric acids.

·         1790 Antoine Lavoisier formulates Table of 31 chemical elements.

·         1780 Lavoisier’s Law of Combustion. Lavoisier proved that the loss of weight in a burned substance is equal to the weight of the lost air in the burning vessel, and that part of the air (oxygen) was essential to combustion. The transition from Stahl’s phlogiston theory to Lavoisier’s oxygen theory marks the beginning of modern chemistry

·         1808-1809 Sir Humphry Davy used the electric battery (developed by Volta in 1800) to separate salts by electrolysis. He was able to separate elemental potassium and sodium in 1807 and calcium, strontium, barium, and magnesium in 1808. He also studied the energies involved in separating these salts, which is now the field of electrochemistry. His laboratory assistant Michael Faraday went on to enhance his work and in the end became more influential in the area of electromagnetism.

·         1814 Spectroscopy for chemical analysis of glowing objects is developed in Germany by Joseph von Fraunhofer

·         1828 Frederich Wohler converts ammonia into “organic” urea

·         1869 Mendeleev's periodic table of the elements.

 

 

 

Elements

 

Hydrogen (H)

·         Hydrogen (H2) is a colorless, odorless highly flammable gas.

·         Hydrogen is the most abundant element, constituting roughly 75% of the universe's elemental matter. Stars in their main sequence are overwhelmingly composed of hydrogen in its plasma state.

·         Elemental hydrogen is relatively rare on Earth, and is industrially produced from hydrocarbons, after which most free hydrogen is used "captively" (meaning locally at the production site), with the largest markets about equally divided between fossil fuel upgrading (e.g. hydrocracking) and in ammonia production (mostly for the fertilizer market).

·         Atomic hydrogen is abundant in space but essentially absent on earth, because it dimerizes to H2

Isotopes

·         The most common naturally occurring isotope of hydrogen (1H) contains one electron and an atomic nucleus of one proton. In ionic compounds it can take on either a positive charge (becoming a cation, a bare proton) or a negative charge (becoming an anion known as a hydride).

·         2H, the other stable hydrogen isotope, is known as deuterium and contains one proton and one neutron in its nucleus. Water enriched in molecules that include deuterium instead of normal hydrogen is called heavy water.

o        Because it would take a very great deal of heavy water to replace 25% to 50% of a human being's body water (70% of body weight) with heavy water, accidental or intentional poisoning with heavy water is unlikely to the point of practical disregard.

·         3H is known as tritium and contains one proton and two neutrons in its nucleus. It is radioactive, and is used in nuclear fusion reactions

History and Uses

·         In 1766 Henry Cavendish was the first to recognize hydrogen gas as a discrete substance, by identifying the gas from a metal-acid reaction as "inflammable air", and further finding that the gas produces water when burned. Cavendish had stumbled on hydrogen when experimenting with acids and mercury. He is usually given credit for its discovery as an element. In 1783 Antoine Lavoisier gave the element the name of hydrogen when he (with Laplace) reproduced Cavendish's finding that water is produced when hydrogen is burned. Lavoisier's name for the gas won out.

·         One of the first uses of H2 was for balloons. The H2 was obtained by reacting sulfuric acid and metallic iron. Infamously, H2 was used in the Hindenburg airship that was destroyed in a midair fire.

·         Having been used as an ingredient in some rocket fuels for several decades H2 is widely discussed in the context of energy. Hydrogen is not an energy source, since it is not an abundant natural resource and more energy is used to produce it than can be ultimately extracted from it. However, it could become useful as a carrier of energy. The hydrogen would then locally be converted into usable energy either via combustion or by electrochemical conversion into electricity in a fuel cell.

 

 

Helium (He)

·         Helium is a colorless, odorless, tasteless chemical element, one of the nearly inert noble gases. It was first identified in 1868.

·         Helium is the second lightest element and the second most abundant element in the universe, created during big bang nucleosynthesis and to a lesser extent from nuclear fusion of hydrogen in stars. On Earth, helium is primarily a product of the radioactive decay of much heavier elements, which emit helium nuclei called alpha particles.

·         On earth helium is found in significant amounts only in natural gas, from which it is extracted at low temperatures by fractional distillation. Throughout the universe, helium is found mostly in a plasma state whose properties are quite different to molecular helium.

·         Helium is used in cryogenics, as a deep-sea breathing gas, for inflating balloons and airships, and as a protective gas for many industrial purposes, such as arc welding.

·         Inhaling a small amount of the gas temporarily changes the quality of a person's voice; however, caution must be exercised as helium is a simple asphyxiant. It is a common misconception that Helium's effects on the voice are related to its density. The real explanation is slightly more complicated. Because Helium is monoatomic (earth's atmosphere consists of over 95% diatomic molecules), its adiabatic index differs from that of air. This means that the speed of sound in helium is faster, and sound of the same frequency has a longer wavelength compared to in air. This difference results in the vibrational modes of the larynx corresponding to higher frequencies, and thus a higher pitched voice.

·         At temperatures near absolute zero, it is a superfluid, a nearly frictionless phase of matter with unusual properties. Unlike any other element, helium will fail to solidify and remain a liquid down to absolute zero at normal pressures.

 

Lithium (Li)

·         Lithium in its pure form does not occur naturally on Earth. It is a soft, silver white metal that tarnishes and oxidizes very rapidly in air and water.

·         Lithium is one of only four elements theorized to have been created in the first three minutes of the universe through a process called Big Bang nucleosynthesis.

·         Lithium forms a minor part of almost all igneous rocks and is also found in many natural brines. Lithium metal is separated from igneous minerals or is extracted from the water of mineral springs (brine pools). The metal is produced electrolytically from a mixture of fused lithium and potassium chloride.

·         Because of its specific heat, the largest of any solid, lithium is used in heat transfer applications, batteries, household appliances such as toasters and microwaves, and in high performance alloys.

·         Lithium compounds are used pharmacologically as a class of mood stabilizing drugs, a neurological effect of the lithium ion Li+.

 

Beryllium (Be)

·         Beryllium is a steel grey, strong, light-weight yet brittle, alkaline earth metal that is primarily used as a hardening agent in alloys.

·         Beryllium was discovered in 1798 in gemstones.  It is a constituent of about 100 minerals. Beryl gemstones vary in color – green are emeralds, blue are aquamarines, etc.

·         Beryllium metal did not become readily available until 1957. Currently, most production of this metal is accomplished by reducing beryllium fluoride with magnesium metal.

·         Beryllium and its salts are toxic substances and potentially carcinogenic. Chronic berylliosis is a pulmonary and systemic granulomatous disease caused by prolonged exposure to beryllium. Although the use of beryllium compounds in fluorescent lighting tubes was discontinued in 1949, potential for exposure to beryllium exists in the nuclear and aerospace industries and in the refining of beryllium metal and melting of beryllium-containing alloys, the manufacturing of electronic devices, and the handling of other beryllium-containing material.

 

Boron (B)

·         Boron is never found free in nature. Boron occurs abundantly in ores such as borax as well as boric acid and other compounds.

·         Borax is widely used in detergents, water softeners, soaps, disinfectants, and pesticides. Its use in detergents is due to its ability to bind to and solvate dirt particles in addition to producing peroxides which have a bleaching effect. It is used as a food additive, but is banned in the United States.

·         Borax occurs naturally in evaporite deposits produced by the repeated evaporation of seasonal lakes. The most commercially important deposits are found in Turkey and near Boron, California and other locations in the American southwest, in Chile, and in Tibet.

·         Elemental boron is used as a dopant in the semiconductor industry, while boron compounds play important roles as light structural materals, nontoxic insecticides and preservatives, and reagents for chemical synthesis, and several hundred other applications.

·         Boron is an essential plant nutrient, and as an ultratrace mineral is necessary for the optimal health of animals, though its physiological role in animals is poorly understood.

 

Carbon

·         Carbon occurs in all organic life and is the basis of organic chemistry.

·         Carbon has the interesting chemical property of being able to bond with itself and a wide variety of other elements, forming nearly ten million known compounds.

·         Carbon has the highest melting/sublimation point of all elements, so that it stays solid at very high temperatures

·         The isotope carbon-14 is commonly used in radioactive dating.

·         The carbon-nitrogen cycle provides some of the energy produced by the Sun and other stars.

Allotropes

·         The three relatively well-known allotropes of carbon are amorphous carbon (charcoal, soot, and coke), graphite, and diamond. Several exotic allotropes have also been synthesized or discovered, including fullerenes, carbon nanotubes, lonsdaleite and aggregated diamond nanorods.

·         Graphite, one of the softest known substances, is combined with clays to form the 'lead' used in pencils.

·         Diamond, the hardest known substance, is used for decorative purposes, and also as drill bits and other applications making use of its hardness.

·         Carbon fibre is mainly used for composite materials, as well as high-temperature gas filtration

·         Fullerenes, in the form of carbon nanotubes, have promising potential uses in the nascent field of nanotechnology.

o        The properties of fullerenes (also called "buckyballs" and "buckytubes") have not yet been fully analyzed. All the names of fullerenes are after Buckminster Fuller, developer of the geodesic dome, which mimics the structure of "buckyballs".

Compounds

·         Carbon dioxide is vital to plant growth.

·         Hydrocarbons are essential to industry in the form of fossil fuels – petroleum, etc.

·         When combined with both oxygen and hydrogen it can form many groups of compounds including fatty acids, which are essential to life, and esters, which give flavor to many fruits.

·         Carbon is added to iron to make steel.

 

 

Nitrogen

·         Nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas, constituting 78% percent of the Earth's atmosphere.

·         Nitrogen is a constituent element of all living tissues and amino acids.

·         Nitrogen was discovered by Daniel Rutherford in 1772.

·         Molecular nitrogen in the atmosphere cannot be used directly by either plants or animals, and needs to be converted to other compounds, or "fixed," in order to be used by life.

o        In certain bacteria, ammonia is produced from atmospheric N2 by enzymes called nitrogenases in a process called nitrogen fixation. Ammonia is also a metabolic product of amino acid deamination. In humans, it is quickly converted to urea, which is much less toxic.

Compunds

Ammonia (NH3)

·         Ammonia is a colorless gas with strong pungent odor

·         The main uses of ammonia are in the production (through nitric acid) of fertilizers, explosives and polymers. It is an ingredient in certain household glass cleaners and can be used as a fertilizer itself.

·         Ammonia is found in small quantities in the atmosphere, being produced from the putrefaction of nitrogenous animal and vegetable matter.

·         In the form of sal-ammoniac (ammonia salts), ammonia was known to the alchemists as early as the 13th century. It was also used by dyers in the Middle Ages in the form of fermented urine to alter the color of vegetable dyes. In the 15th century, ammonia was obtained by the action of alkalis on sal-ammoniac. At a later period, sal-ammoniac was obtained by distilling the hoofs and horns of oxen and neutralizing the resulting carbonate with hydrochloric acid. Gaseous ammonia was first isolated by Joseph Priestley in 1774

·         Before the start of World War I most ammonia was obtained by the dry distillation of nitrogenous vegetable and animal waste products, including camel dung or bird guano; additionally, it was produced by the distillation of coal and by the decomposition of ammonium salts by alkaline hydroxides such as quicklime

·         The Haber process to produce ammonia from the nitrogen contained in the air was developed by Fritz Haber and Carl Bosch in 1909. It was first used on an industrial scale to produce explosives by the Germans during World War I following the allied blockade that cut off the supply of nitrates from Chile.

·         Today, the typical modern ammonia-producing plant first converts hydrocarbons (natural gas, liquefied petroleum gas, or naphtha) into gaseous hydrogen. The hydrogen is then catalytically reacted with nitrogen (derived from process air) to form anhydrous liquid ammonia.

Nitrates

·         Sodium and potassium nitrates have long been used as an ingredient in explosives and in solid rocket propellants, as well as in glass and pottery enamel, and as a food preservative, and has been mined extensively for those purposes.

·         They are also known as caliche or saltpeter.

·         Prior to the large-scale industrial fixation of nitrogen through the Haber process, a major source of Potassium nitrate was the deposits crystallising from cave walls or the drainings of decomposing organic material. Dung-heaps were a particularly common source: ammonia from the decomposition of urea and other nitrogenous materials would undergo bacterial oxidation to produce nitrate. The world's largest natural deposits of caliche ore were in the Atacama desert of Chile, and many deposits were mined for over a century, until the 1940s.

·         Potassium Nitrate is also a main component in stump remover; it accelerates the natural decomposition of the stump

Nitric acid

·         Nitric acid is used in the manufacture of explosives such as nitroglycerin, trinitrotoluene (TNT) and Cyclotrimethylenetrinitramine (RDX), as well as fertilizers such as ammonium nitrate. Nitric and sulfuric acids are mixed with glycerin (nitroglycerine),  toluene (TNT), or cellulose (nitrocellulose)

·         The mixture of nitric and hydrochloric acids was known as aqua regia (royal water), celebrated for its ability to dissolve gold (the king of metals).

Nitroglycerin

·         Nitroglycerin is used in the manufacture of explosives, specifically dynamite.

·         Nitroglycerin is also used medically as a vasodilator to treat angina pectoris. These effects arise because nitroglycerin is converted to nitric oxide in the body (by a mechanism that is not completely understood), and nitric oxide is a natural vasodilator.

·         Nitroglycerin was discovered in 1847. The best manufacturing process was developed by Alfred Nobel in the 1860s. His company exported a liquid combination of nitroglycerin and gunpowder as 'Swedish Blasting Oil', but the extreme danger as a result of its extreme instability led to the development of dynamite, mixing the nitroglycerine with inert  or combustible absorbents (e.g., nitrocellulose to produce the yellow gel, blasting gelatine).

Nitrocellulose

·         Nitrocellulose is a major component of guncotton and smokeless gunpowder

o        In the 1830s it was found that combining nitric acid with wood or paper would create explosive material, but it was too unstable to be practically useful

o        In 1846 Christian Friedrich Schönbein was working when he spilled a bottle of concentrated nitric acid on the kitchen table. He wiped it up with a cotton apron and hung the apron on the stove door to dry; there was a flash as the apron exploded. His preparation method was the first to be widely imitated — one part of fine cotton wool to be immersed in fifteen parts of an equal blend of sulfuric and nitric acids. However the sensitivity of the material during production led to its discontinuation.

o        In the 1880s guncotton was processed to the more stable forms of smokeless gunpowder

·         Photographic film

o        Nitrocellulose was used as the first flexible film base, beginning with Eastman Kodak in 1889. Camphor is used as plasticizer for nitrocellulose film. It was used until 1933 for X-ray films (where its flammability hazard was most acute) and for motion picture film until 1951. It was replaced by safety film with an acetate base.

·         Nitrocellulose membrane or nitrocellulose paper is a sticky membrane used for Western blots and immobilizing DNA. It is also used for immobilization of proteins, due to its non-specific affinity for amino acids. Nitrocellulose is widely used as support in diagnostic tests where antigen-antibody binding occur, e.g. pregnancy tests, U-Albumin tests and CRP.

·         When dissolved in ether or other organic solvents, the solution is called collodion, which has been used as a wound dressing and carrier of topical medications since the U.S. Civil War. To this day it is used in Compound W Wart Remover as a carrier of salicylic acid, the active ingredient. Collodion was also used as the carrier for silver salts in some very early photographic emulsions, particularly spread in thin layers on glass plates.

·         Magician's "flash paper", sheets of paper or cloth made from nitrocellulose, which burn almost instantly, with a bright flash, and leave no ash.

Cyanides (CN)

·         Hydrogen cyanide poisoning is also common as a result of smoke inhalation after house fires. Ingestion is equally dangerous, although this route of absorption is usually deliberate (suicidal or criminal).

·         Many cyanide-containing compounds are highly toxic, but many are not. Prussian blue, iron cyanide, is a common pigment.

 

Oxygen (O)

·         Oxygen is the second most common element on Earth, composing around 49% of the Earth's crust, and is the third most common element in the universe. On Earth, it is usually covalently or ionically bonded to other elements.

·         Unbound oxygen (O2) first appeared in significant quantities on Earth during the Paleoproterozoic era (between 2.5 billion years ago and 1.6 billion years ago) as a product of the metabolic action of early anaerobes (archaea and bacteria). The atmospheric abundance of free oxygen in later geological epochs and up to the present has been largely driven by photosynthetic organisms; roughly three quarters of the free element being produced by algae in the oceans, and one quarter from terrestrial plants.

·         Oxygen is essential to respiration

·         Ozone (O3) is an allotrope of oxygen that is much less stable than O2. It is present in low concentrations throughout the Earth's atmosphere. It has many industrial and consumer applications.

·         Due to its electronegativity, oxygen forms chemical bonds with almost all other elements hence the origin of the original definition of oxidation. The only elements to escape the possibility of oxidation are a few of the noble gases, and fluorine. The most famous of these oxides is water (H2O). Other well known examples include compounds of carbon and oxygen, such as carbon dioxide (CO2), alcohols (R-OH), carbonyls, (R-CO-H or R-CO-R)), and carboxylic acids (R-COOH). Oxygenated radicals such as chlorates (ClO3−), perchlorates (ClO4−), chromates (CrO42−), dichromates (Cr2O72−), permanganates (MnO4−), and nitrates (NO3−) are strong oxidizing agents in and of themselves.

 

Flourine (F)

·         Fluorine is the most chemically reactive and electronegative of all the elements. In its pure form, it is a poisonous, pale, yellow-green gas, with chemical formula F2. Like other halogens, molecular fluorine is highly dangerous; it causes severe chemical burns on contact with skin.

·         Fluorine in the form of fluorspar (also called fluorite) (calcium fluoride) was described in 1530. In 1886, fluorine was isolated after almost 74 years of continuous effort.

·         The first large scale production of fluorine was needed for the atomic bomb Manhattan project in World War II where the compound uranium hexafluoride (UF6) was used to separate the 235U and 238U isotopes of uranium.

·         Fluorine can often be substituted for hydrogen when it occurs in organic compounds.

·         Compounds of fluorine, including sodium fluoride (NaF), are used in toothpaste to prevent dental cavities. These compounds are also added to municipal water supplies, a process called water fluoridation.

 

Neon (Ne)

·         Neon is a colorless, nearly inert noble gas. It is found in air in trace amounts. It was discovered in 1898.

·         Neon gives a distinct reddish glow when used in vacuum discharge tubes and neon lamps. It is also used as a refrigerant.

 

Sodium (Na)

·         Sodium is a soft, silvery, highly reactive alkali metal. Owing to its high reactivity, sodium is found in nature only as a compound and never as the free element.

·         Sodium was first isolated by Sir Humphry Davy in 1807 by passing an electric current through molten sodium hydroxide.

·         Sodium quickly oxidizes in air so must be stored in an inert environment such as kerosene.

·         Sodium reacts exothermically with water: small pea-sized pieces will swim around the surface of the water until they are consumed by it, whereas large pieces will explode.

·         Sodium is in great quantity in the earth's oceans as chloride. It is also a component of many earthly minerals, and it is an essential element for animal life.

·         Sodium ions are necessary for regulation of blood and body fluids, transmission of nerve impulses, heart activity, and certain metabolic functions. Interestingly, sodium is needed by animals, which maintain high concentrations in their blood and extracellular fluids, but it is not needed by plants.

·         The most common sodium salt, sodium chloride (table salt), used for seasoning and food preservation, has been an important commodity in human activities. Salary refers to salarium, the perquisite given to Roman soldiers for the purpose of buying salt.

·         The human requirement for sodium in the diet is less than 500 mg per day, which is typically less than a tenth as much as many diets "seasoned to taste." Most people consume far more sodium than is physiologically needed. For certain people with salt-sensitive blood pressure, this extra intake may cause a negative effect on health.

 

Magnesium

·         Magnesium is the eighth most abundant element and constitutes about 2% of the Earth's crust, and it is the third most plentiful element dissolved in seawater.

·         Magnesium ion is essential to all living cells.

·         The free element (metal) is not found in nature.

·         Once produced from magnesium salts, the metal is primarily used as an alloying agent to make aluminium-magnesium alloys

·         Although magnesium is found in over 60 minerals, only dolomite, magnesite, brucite, carnallite, talc, and olivine are of commercial importance.

·         Magnesium is the third most commonly used structural metal, following steel and aluminum.

 

Aluminum

·         Aluminum is found primarily in the bauxite ore.

·         It is remarkable for its resistance to corrosion and its light weight. Aluminum is used in many industries to manufacture a large variety of products and is very important to the world economy. Structural components made from aluminum and its alloys are vital to the aerospace industry and very important in other areas of transportation and building.

·         Pure aluminum has a low tensile strength, but readily forms alloys with many elements such as copper, zinc, magnesium, manganese and silicon. Today almost all materials that claim to be aluminum are actually an alloy thereof.

·         Friedrich Wöhler is generally credited with isolating aluminum in 1827 by mixing anhydrous aluminum chloride with potassium. Aluminum was later extracted from bauxite ore.

·         Charles Martin Hall patented in 1886 for an electrolytic process to extract aluminum from minerals which was cheaper, and is now the principal method in common use throughout the world. Hall, with the financial backing of Alfred E. Hunt, started the Pittsburgh Reduction Company, renamed to Aluminum Company of America in 1907, later shortened to Alcoa.

·         Germany became the world leader in aluminum production soon after Adolf Hitler's rise to power. By 1942, however, new hydroelectric power projects such as the Grand Coulee Dam gave the United States something Nazi Germany could not hope to compete with, namely the capability of producing enough aluminum to manufacture sixty thousand warplanes in four years

·         Although aluminum is the most abundant metallic element in Earth's crust, it is very rare in its free form.

·         Aluminum was once considered a precious metal more valuable than gold. Napoleon III of France had a set of aluminum plates reserved for his finest guests. Aluminum has been produced in commercial quantities for just over 100 years.

·         Aluminum is a neurotoxin that alters the function of the blood-brain barrier. It is one of the few abundant elements that appears to have no beneficial function to living cells.

 

Silicon (Si)

·         Silicon is the second most abundant element in the Earth's crust, 26% by mass. It does not occur free in nature. It mainly occurs in minerals consisting of silicon dioxide in different crystalline forms (quartz, chalcedony, opal) and as silicates (various minerals containing silicon, oxygen and one or another metal), for example feldspar, granite, asbestos. These minerals occur in clay, sand and various types of rock like granite and sandstone.

·         Silicon is the principal component, in the form of silica and silicates, in glass, cement, and ceramics.

·         Silicon is a component of silicones, a name for various plastic substances often confused with silicon itself.

o        Silicones have many uses, such as lubricants, adhesives, construction sealants, gaskets, breast implants, dishware, Silly Putty, and many other products. Due to their thermal stability and relatively high melting and boiling points, silicones are often used where organic polymers are not applicable. Their unreactivity generally makes them non-toxic.

·         Silicon is widely used in semiconductors because it remains a semiconductor at higher temperatures than the semiconductor Germanium and because its native oxide  is easily grown in a furnace and forms a better semiconductor/dielectric interface than almost all other material combinations.

·         The largest application of pure silicon (metallurgical grade silicon) is in aluminum - silicon alloys, often called "light alloys", to produce cast parts, mainly for automotive industry (this represents about 55 % of the world consumption of pure silicon)

 

Phosphorus (P)

·         Phosphorus is commonly found in inorganic phosphate rocks and in all living cells.

·         Phosphorus exists in several allotropes, most commonly white, red and black. White phosphorus glows in the dark and is highly explosive as well as toxic. Red phosphorus is more stable and does not catch fire in air. Black phosphorus is amorphous and is the least reactive allotrope.

·         Due to its high reactivity, phosphorus is never found as a free element in nature. Phosphate rock, which is partially made of apatite (an impure tri-calcium phosphate mineral), is an important commercial source of this element. Phosphorus, in its common form, is a waxy white (or yellowish) solid that has a characteristic, disagreeable smell similar to that of garlic.

o        Apatite is one of few minerals that are produced and used by biological systems. Hydroxylapatite is the major component of tooth enamel, and a large component of bone.

·         It emits a faint glow upon exposure to oxygen. The glow was the attraction of its discovery around 1669, but the mechanism for that glow was not fully described until 1974.

o        It was first discovered through a preparation from urine. Chemists attempted to distill salts by evaporating urine, and in the process produced a white material that glowed in the dark and burned brilliantly. Since that time, phosphorescence has been used to describe substances that shine in the dark without burning.

o        A reaction with oxygen takes place at the surface of the solid (or liquid) phosphorus, forming short-lived molecules HPO and P2O2 and they both emit visible light. Although the term phosphorescence is derived from phosphorus, the reaction is properly called luminescence (glowing by its own reaction)

·         Phosphorus is an essential element for living organisms. Living cells utilize phosphate to transport cellular energy via adenosine triphosphate (ATP).

·         The most important commercial use of phosphorus-based chemicals is the production of fertilizers. They are also widely used in explosives, nerve agents, friction matches, fireworks, pesticides, toothpaste, and detergents

·         Concentrated phosphoric acids, which can consist of 70% to 75% P2O5 are very important to agriculture and farm production in the form of fertilizers. Global demand for fertilizers led to large increases in phosphate (PO43-) production in the second half of the 20th century

o        In the 1850s-1860s German chemist Justus von Liebig burns plants and analyzes the ashes.  He determines that phosphorus and nitrogen are major components and nutrients of plants.  He invents nitrogen and phosphorus fertilizer. This doubles crop yields.

·         White phosphorus is used in military applications as incendiary bombs, for smoke-screening as smoke pots and smoke bombs, and in tracer ammunition.

·         Red phosphorus is essential for manufacturing matchbook strikers, flares, safety matches, and cap guns.

·          Phosphorus was first made commercially, for the match industry, in the 19th century, by distilling off phosphorus vapor from precipitated phosphates heated in a retort. The precipitated phosphates made from ground-up bones that had been de-greased and treated with strong acids. This process became obsolete in the late 1890s when the Electric arc furnace was adapted to reduce phosphate rock. The electric furnace method allowed production to increase to the point phosphorus could be used in World War I as incendiaries, smoke screens and tracer bullets

 

Sulfur (S)

·         Sulfur, in its native form, is a yellow crystalline solid. In nature, it can be found as the pure element or as sulfide and sulfate minerals.

·         It is an essential element for life and is found in two amino acids - homocysteine and taurine – although they are not coded for by DNA nor are they part of the primary structure of proteins.

·         Its commercial uses are primarily in fertilizers but it is also widely used in gunpowder, matches, insecticides and fungicides.

·         Although sulfur is infamous for its smell—frequently compared to rotten eggs—the odor is actually characteristic of hydrogen sulfide (H2S); elemental sulfur has a faint odor similar to matches

·         Sulfuric acid production is the major end use for sulfur, and consumption of sulfuric acid has been regarded as one of the best indices of a nation's industrial development. More sulfuric acid is produced in the United States every year than any other industrial chemical.

·         Sulfur is also used in batteries, detergents, the vulcanization of rubber, fungicides, and in the manufacture of phosphate fertilizers. Sulfites are used to bleach paper and as a preservative in wine and dried fruit. Because of its flammable nature, sulfur also finds use in matches, gunpowder, and fireworks. Sodium or ammonium thiosulfate is used as photographic fixing agents. Magnesium sulfate, better known as Epsom salts, can be used as a laxative, a bath additive, an exfoliant, or a magnesium supplement for plants. Sulfur is used as the light-generating medium in the rare lighting fixtures known as sulfur lamps.

·         Sulfur was known in ancient times, and is referred to in the Biblical Pentateuch (Genesis) where hell is supposed to smell like sulfur – i.e. “fire and brimstone (sulfur)”. In the late 1770s, Antoine Lavoisier helped convince the scientific community that sulfur was an element and not a compound.

·         Elemental sulfur can be found near hot springs and volcanic regions in many parts of the world, especially along the Pacific Ring of Fire. Such volcanic deposits are currently exploited in Indonesia, Chile, and Japan.  In 1867, sulfur was discovered in underground deposits (salt domes) in Louisiana and Texas. The overlying layer of earth was quicksand, prohibiting ordinary mining operations. Therefore the Frasch process was utilized. The sulfur in these deposits is believed to come from the action of anaerobic bacteria on sulfate minerals, especially gypsum.

·         Common naturally occurring sulfur compounds include the metal sulfides, such as pyrite (iron sulfide – fool’s gold), cinnabar (mercury sulfide), galena (lead sulfide – the first semiconductor discovered), sphalerite (zinc sulfide) and stibnite (antimony sulfide); and the metal sulfates, such as gypsum (calcium sulfate), alunite (potassium aluminium sulfate), and barite (barium sulfate). It occurs naturally in volcanic emissions, such as from hydrothermal vents, and from bacterial action on decaying sulfur-containing organic matter. The distinctive colors of Jupiter's volcanic moon, Io, are from various forms of molten, solid and gaseous sulfur.

 

Chlorine (Cl)

·         As the chloride ion (Cl-), which is part of common salt (NaCl) and other compounds, it is abundant in nature and necessary to most forms of life, including humans.

·         In its elemental form (Cl2) it is a pale green gas which has a disagreeable suffocating odor and is poisonous. Chlorine is a powerful oxidant and is used in bleaching and disinfectants.

·         It combines readily with nearly all other elements, although it is not as extremely reactive as fluorine. It is a member of the salt-forming halogen series and is extracted from chlorides through oxidation often by electrolysis.

·         Chlorine was discovered in 1774 by Carl Wilhelm Scheele, who mistakenly thought it contained oxygen. Chlorine was given its current name in 1810 by Sir Humphry Davy, who insisted that it was in fact an element.

·         Chlorine gas, also known as bertholite, was first used as a weapon against human beings in WWI by Germany.

·         In nature, chlorine is found mainly as the chloride ion, a component of the salt that is deposited in the earth or dissolved in the oceans. Most chloride salts are soluble in water, thus, chloride-containing minerals are usually only found in abundance in dry climates or deep underground.

·         Chlorination is used (in the form of hypochlorous acid) to kill bacteria and other microbes from drinking water supplies and swimming pools.

 

Argon (Ar)

·         Argon is present in the Earth's atmosphere at slightly less than 1%, making it the most common noble gas on Earth.

·         Argon is used in incandescent lighting and other applications (such as welding) in which nitrogen is not sufficiently inert. Argon will not react with the filament of light bulbs even at high temperatures.

·         Cryosurgery procedures such as cryoablation use liquefied argon to destroy cancer cells.

·         Due to its inert qualities, it is commonly used by museum conservators to protect old materials or documents, which are prone to gradual oxidization in the presence of air.

 

Potassium (K)

·         Potassium is a soft silvery-white metallic alkali metal that occurs naturally bound to other elements in seawater and many minerals. It oxidizes rapidly in air and is very reactive, especially towards water. In many respects, potassium and sodium are chemically similar, although organisms in general, and animal cells in particular, treat them very differently.

·         Potassium makes up about 2% of the Earth's crust and is the seventh most abundant element in it. As it is very electropositive, potassium metal is difficult to obtain from its minerals. It is never found free in nature. Potassium can be isolated through electrolysis of its hydroxide in a process that has changed little since Davy.

·         Potassium was discovered in 1807 by Sir Humphrey Davy, who derived it from potash. Potassium was the first metal that was isolated by electrolysis.

·         It is primarily used in fertilizer as either the chloride, sulfate or carbonate - not as the oxide.

·         Potassium hydroxide is an important industrial chemical used as a strong base.

·         Potassium nitrate is used in gunpowder (black powder). An older term for KNO3 is saltpeter.

·         Glass treated with liquid potassium is much stronger than regular glass.

·         Potassium is an essential component needed in plant growth and is found in most soil types. In animal cells potassium ions are vital to keeping cells alive (the Na-K pump)

·         Potassium chloride is used as a substitute for table salt and is also used to stop the heart, e.g. in cardiac surgery and in executions by lethal injection in solution.

·         Potash (or carbonate of potash) is an impure form of potassium carbonate (K2CO3) mixed with other potassium salts. Potash has been used since antiquity in the manufacture of glass and soap and as a fertilizer. The name refers to its discovery in the water-soluble fraction of wood ash. Until the 20th century, potash was one of the most important industrial chemicals in Europe. It was produced primarily in the forested areas of Europe, Russia and North America; refined from the ashes of broadleaved trees. Potash production provided settlers in North America a way to obtain badly needed cash and credit while they were in the process of clearing their wooded land for crops. Ashes from hardwood trees could then be used to make lye, which could either be used to make soap or boiled down to produce valuable potash. Potash was so important at that time that it was the subject of first patent issued in the United States in 1790.

o        To create potash, take an open-bottomed barrel, and place it on a stone base with a groove cut into it, which will direct the resulting liquid into another container. Then place a layer of straw at the bottom, covered by a layer of sticks. This filter layer will prevent the ashes from contaminating the solution. Then fill the barrel with wood-ashes and pour water over it. The water will leach out the potash into the receptacle. This product will be of variable quality. Historically, it was measured by seeing how high an egg would float in the solution. The liquid may be boiled away to give a black, impure potash.If desired, the potash could be further refined by baking in a kiln to produce a less impure form of potassium carbonate, known as pearlash for its pearly white color.

o        Potash is still used in glass manufacture.

o        The principal source of potassium, potash ore, is mined in California, Germany, New Mexico, Utah, and Saskatchewan

 

Calcium (Ca)

·         Calcium is a soft grey alkaline earth metal that is the fifth most abundant element in the Earth's crust

·         Calcium is not naturally found in its elemental state. Calcium is found mostly in soil systems as limestone, gypsum and fluorite.

·         Calcium was known as early as the first century when the Ancient Romans prepared lime as calcium oxide. It was not actually isolated until 1808 in England when Sir Humphrey Davy electrolyzed a mixture of lime and mercuric oxide.

·         It is used as a reducing agent in the extraction of thorium, zirconium and uranium.

·         It is essential for living organisms, particularly in cell physiology, and is the most common metal in many animals. Calcium is essential in muscle contraction, oocyte activation, building strong bones and teeth, blood clotting, nerve impulse transmission, regulating heartbeat, and fluid balance within cells.

·         Lime is a general term for various naturally occurring minerals and materials derived from them, in which carbonates, oxides and hydroxides of calcium predominate. These materials are used in large quantities as building and engineering materials (including limestone products, concrete and mortar) and as chemical feedstocks. The rocks and minerals from which these materials are derived, typically limestone or chalk, are composed primarily of calcium carbonate. They may be cut, crushed or pulverized and/or chemically altered. 'Burning' (calcination) converts them into the highly caustic material quicklime (calcium oxide) and through subsequent addition of water, into the less caustic (but still strongly alkaline) slaked lime (calcium hydroxide). When the term is encountered in an agricultural context, it probably refers to Agricultural lime. Otherwise it most commonly means slaked lime, as the more dangerous form is usually described more specifically as quicklime or burnt lime. When lime is mixed with sand, it hardens into a mortar and is turned into plaster by carbon dioxide uptake. Mixed with other compounds, lime forms an important part of Portland cement.

 

Scandium (Sc)

·         Scandium occurs in rare minerals from Scandinavia. The main application by volume is in aluminium-scandium alloys for the aerospace industry and for sports equipment. It is also used for high-intensity light bulbs.

 

Titanium (Ti)

·         Titanium is a light, strong, lustrous, corrosion-resistant transition metal with a white-silvery-metallic color.

·         Titanium is used in strong light-weight alloys (most notably with iron and aluminium) used in aircraft, armour plating, naval ships, spacecraft and missiles. In powdered form it is used in materials such as graphite composites.

·         It is used in medical implants, such as joint replacements or plates. Since titanium is non-ferromagnetic, patients with titanium implants can be safely examined with magnetic resonance imaging (convenient for long-term implants). Titanium also has the unusual ability to osseointegrate

·         Its most common compound, titanium dioxide, is used in white pigments, for example correction fluid, white paint, and toothpaste.

·         The element occurs in numerous minerals with the main sources being rutile and ilmenite, which are widely distributed over the Earth.

·         The metal has always been difficult to extract from its various ores. Pure metallic titanium (99.9%) was first prepared in 1910 by the Hunter process. Titanium metal was not used outside the laboratory until 1946 when titanium could be commercially produced by reducing titanium tetrachloride with magnesium in the Kroll process which is the method still used today.

·         In 1950–1960s the Soviet Union attempted to corner the world titanium market as a tactic in the Cold War to prevent the American military from utilizing it. In spite of these efforts, the U.S. obtained large quantities of titanium when a European company set up a front for the U.S. foreign intelligence agencies to purchase it.

·         Titanium metal is always bonded to other elements in nature. It is the ninth-most abundant element in the Earth's crust (0.63%) and is present in most igneous rocks and in sediments derived from them. It is widely distributed and occurs in many minerals, however only ilmenite and rutile have significant economic importance, yet even they are difficult to find in high concentrations. Because it reacts easily with oxygen and carbon at high temperatures, it is difficult to prepare pure titanium metal, crystals, or powder. Significant titanium ore deposits exist in Australia, New Zealand, Scandinavia, North America, and Malaysia.

·         Although titanium metal is relatively uncommon, due to the cost of extraction, titanium dioxide is cheap, nontoxic, readily available in bulk, and very widely used as a white pigment

 

Vanadium (V)

·         A rare, soft and ductile element, vanadium is found combined in certain minerals (never unbound) and is used mainly to produce certain alloys. It is one of the 26 elements commonly found in living things, particularly nitrogen-fixing organisms and sea squirts.

 

Chromium (Cr)

·         Chromium is a steel-gray, lustrous, hard metal. It is used to impart corrosion resistance and a shiny finish, such as in chrome plating or stainless steel.

·         Chromium is what makes a ruby red. It is used as a red or green coloring agent.

·         Chromium is required in trace amounts for sugar metabolism in humans, and its deficiency can cause chromium deficiency

·         Chromium is mined as chromite (FeCr2O4) ore. Roughly half the chromite ore in the world is produced in South Africa.

 

Manganese (Mn)

·         Manganese is a gray-white metal, resembling iron.

·         Manganese is essential to iron and steel production which accounts for most manganese demand.

·         Manganese (Latin magnes, meaning "magnet") was in use in prehistoric times; paints that were pigmented with manganese dioxide can be traced back 17,000 years. The Egyptians and Romans used manganese compounds in glass-making, to either remove color from glass or add color to it. Manganese can be found in the iron ores used by the Spartans. Some speculate that the exceptional hardness of Spartan steels derives from the inadvertent production of an iron-manganese alloy.

·         The Swedish chemist Scheele was the first to recognize that manganese was an element, and his colleague, Johan Gottlieb Gahn, isolated the pure element in 1774

·         Manganese is an essential trace nutrient in all forms of life. The classes of enzymes that have manganese cofactors are very broad

·         Manganese occurs principally as pyrolusite (MnO2), and to a lesser extent as rhodochrosite (MnCO3). Land-based resources are large but irregularly distributed; those of the United States are very low grade and have potentially high extraction costs. South Africa and Ukraine account for more than 80% of the world's identified resources;

 

Iron (Fe)

·         Iron is the second most abundant metal on Earth (the first being magnesium), and is believed to be the tenth most abundant element in the universe

·         It is possible the Earth's inner core consists of a single iron crystal, although it is more likely to be a mixture iron and nickel. The large amount of iron in the Earth is thought to create its magnetic field

·         Iron is a metal extracted from iron ore, and is almost never found in the free elemental state. In order to obtain elemental iron, the impurities must be removed by chemical reduction.

·         Iron is found as Fe2O3—the form of iron oxide (rust) found as the mineral hematite, and FeS2—Pyrite (fool's gold). Iron oxide is a soft sandstone-like material with limited uses on its own.

·         Iron is the most used of all the metals, comprising 95% of all the metal tonnage produced worldwide. Its combination of low cost and high strength make it indispensable, especially in applications like automobiles, ships, and structural components for buildings.

·         Iron (as Fe2+, ferrous ion) is a necessary trace element used by all living organisms. Iron-containing enzymes, usually containing heme prosthetic groups e.g. hemegloblin, participate in cataysis of oxidation reactions in biology, and in transport of a number of soluble gases,.

·         History of Ironworking

Steel         

·         Steel is an iron alloy with carbon (0.02-1.7%), or another hardening agent.

·         Stainless steels contain a minimum of 10% chromium, often combined with nickel, to resist corrosion (rust). Some stainless steels are nonmagnetic.

·         Uses: wires, structural girders, car bodies, appliances, cutlery, etc.

·         Steel: Economics

 

 

Cobalt (Co)

·         Cobalt is a ferromagnetic metal found in various ores, not as a free metal, and is used in the preparation of magnetic, wear-resistant, and high-strength alloys. Its compounds are used in the production of inks, paints, and varnishes – cobalt blue and cobalt green. It was first isolated in 1737.

·         It is frequently associated with nickel, and both are characteristic ingredients of meteoric iron.

·         Mammals require small amounts of cobalt salts.

·         Cobalt-60, an artificially produced radioactive isotope of cobalt, is an important radioactive tracer and cancer-treatment agent. Artificial cobalt-60 is created by bombarding a cobalt-59 target with a slow neutron source, usually californium-252 moderated through water to slow the neutrons down

·         The world's major producers of cobalt are the Democratic Republic of the Congo, China, Zambia, Russia and Australia.

 

Nickel (Ni)

·         Because of its inertness to oxidation, it is used in the smaller coins, for plating iron, brass, etc. Nickel is used in many industrial and consumer products, including stainless steel, magnets, coinage, and special alloys. It is also used for plating and as a green tint in glass. Nickel is pre-eminently an alloy metal, and its chief use is in the nickel steels and nickel cast irons, of which there are innumerable varieties.

·         Nickel is found as a constituent in most meteorites and often serves as one of the criteria for distinguishing a meteorite from other minerals

·         It is magnetic, and is very frequently accompanied by cobalt, both being found in meteoric iron.

·         It is chiefly valuable for the alloys it forms

·         Nickel use is ancient, and can be traced back as far as 3500 BC.

·         The bulk of the nickel mined comes from two types of ore deposits

 

Copper (Cu)

·         Copper is a ductile metal with excellent electrical conductivity, and finds extensive use as an electrical conductor (wiring), as a building material (pipes), and as a component of various alloys.

·         Copper is one of the few metals to naturally occur as an uncompounded mineral

·         Copper was known to some of the oldest civilizations - a copper pendant was found Iraq that dates to 8700 BC. By 5000 BC, there are signs of copper smelting, the refining of copper from simple copper compounds such as malachite or azurite.

·         Copper is essential in all higher plants and animals. It is carried mostly in the bloodstream and is found in a variety of enzymes

·         Pennies are 2% copper-plated (98% Zinc), nickels are 75% copper, dimes and quarters are 92% copper (the balance of each being nickel).

Bronze

·         Bronze is an alloy of copper and tin

·         There bronze artifacts from Sumerian cities that date to 3000 BC. The Bronze Age is taken as 2500 BC to 600 BC.

Brass

·         Brass is an alloy of copper and zinc

 

Zinc (Zn)

·         Zinc is a moderately reactive bluish-white metal that burns with a bright greenish flame, giving off plumes of zinc oxide. It does not exist as a free metal but only in ores, such as calamine

·         Zinc is used to galvanize steel to prevent corrosion. It is used in alloys such as brass and is the primary metal in the US penny.  Zinc oxide is used as a white pigment in paints, and as an over-the-counter ointment for skin protection. Calamine lotion (as opposed to the ore) is a mixture of zinc oxide with about 0.5% iron(III) oxide (Fe2O3), and is used as an antipruritic (anti-itch)

·         Zinc alloys have been used for centuries, as brass goods dating to 1000–1400 BC have been found in Israel. Because of the low boiling point and high chemical reactivity of this metal (isolated zinc would tend to go up the chimney rather than be captured), the true nature of this metal was not understood in ancient times. The manufacture of brass was known to the Romans by about 30 BC, using a technique where calamine and copper were heated together in a crucible.

·         Zinc is an essential element for all life. It is required as a cofactor by thousand of enzymes, and its deficiency leads to disease

 

Gallium (Ga)

·         A rare, soft silvery metallic poor metal, gallium is a brittle solid at low temperatures but liquefies slightly above room temperature and indeed will melt in the hand.

·         Gallium does not exist in free form in nature, nor do any high-gallium minerals exist to serve as a primary source of extraction of the element or its compounds. It occurs only in trace amounts in bauxite and zinc ores.

·         Gallium metal expands when it solidifies and shares the higher-density liquid state with only a few materials like water and bismuth. Gallium also attacks most other metals by diffusing into their metal lattice

·         An important application is in the compound gallium arsenide, used as a semiconductor, most notably in light-emitting diodes (LEDs).

 

Germanium (Ge)

·         Germanium is a lustrous, hard, silver-white metalloid that is chemically similar to tin.

·         This element is found in argyrodite (sulfide of germanium and silver); coal; germanite; zinc ores; and other minerals. Germanium forms a large number of organometallic compounds

·         Germanium is a semiconductor, and the development of the germanium transistor opened the door to countless applications of solid state electronics. From 1950 through the early 1970s, this area provided an increasing market for germanium, but then high purity silicon began replacing germanium in transistors, diodes, and rectifiers. Silicon has superior electrical properties, but requires much higher purity samples—a purity which could not be commercially achieved in the early days. Meanwhile, demand for germanium in fiber optics communication networks, infrared night vision systems, and polymerization catalysts increased dramatically. These end uses represented 85% of worldwide germanium consumption.

·         Unlike most semiconductors, germanium has a small band gap, allowing it to efficiently respond to infrared light. It is therefore used in infrared spectroscopes and other optical equipment which require extremely sensitive infrared detectors.

·         Germanium transistors are still used in some stompboxes by musicians who wish to reproduce the distinctive tonal character of the "fuzz"-tone from the early rock and roll era. Vintage stompboxes known to contain germanium transistors have shown marked increases in collector value for this reason alone

 

Arsenic (As)

·         Arsenic is a metalloid that has many allotropic forms; yellow, black and gray are a few that are regularly seen.

·         Arsenic and its compounds are used as pesticides, herbicides, insecticides and various alloys

·         Arsenic is very similar chemically to its predecessor phosphorus, so much so that it will partly substitute for phosphorus in biochemical reactions and is thus poisonous. Arsenic disrupts ATP production through several mechanisms. When heated rapidly it oxidizes to arsenic trioxide; the fumes from this reaction have an odor resembling garlic.

·         The application of most concern to the general public is probably that of wood which has been treated with chromated copper arsenate ("CCA", or "Tanalith", and the vast majority of older "pressure treated" wood). CCA timber is still in widespread use in many countries, and was heavily used during the latter half of the 20th century. Although widespread bans exist, the most serious risk is presented by the burning of CCA timber. Recent years have seen serious human poisonings resulting from the ingestion - directly or indirectly - of wood ash from CCA timber (the lethal human dose is approximately 20 grams of ash). Scrap CCA construction timber continues to be widely burnt through ignorance, in both commercial, and domestic fires.

·         During the 18th, 19th, and 20th centuries, a number of arsenic compounds have been used as medicines, including arsphenamine (by Paul Ehrlich) and arsenic trioxide (by Thomas Fowler). Arsphenamine as well as Neosalvarsan was indicated for syphilis and trypanosomiasis, but has been superseded by modern antibiotics. Arsenic trioxide has been used in a variety of ways over the past 200 years, but most commonly in the treatment of cancer.

·         Arsenic has been known and used in Persia and elsewhere since ancient times. As the symptoms of arsenic poisoning were somewhat ill-defined, it was frequently used for murder until the advent of the Marsh test, a sensitive chemical test for its presence. (Another less sensitive but more general test is the Reinsch test.) Due to its use by the ruling class to murder one another and its incredible potency and discreetness, arsenic has been called the Poison of Kings and the King of Poisons.

·         Albertus Magnus is believed to have been the first to isolate the element in 1250. In 1649 Johann Schroeder published two ways of preparing arsenic.

·         Arsenopyrite also called mispickel (FeSAs) is the most common mineral from which, on heating, the arsenic sublimes leaving ferrous sulfide. Other arsenic minerals include realgar, mimetite, cobaltite and erythrite.

 

Selenium (Se)

·         Selenium is not found in the free state in nature. It is a nonmetal that is chemically related to sulfur.

·         It is toxic in large amounts, but trace amounts of it, forming the active center of certain enzymes, are necessary for the function of all cells in (probably) all living organisms.

·         Isolated selenium occurs in several different forms, but the most stable of these is a dense gray semimetal (semiconductor) form that conducts electricity better in the light than in the dark, and is used in photocells. Selenium also exists in many nonconductive forms: a black glass-like substance, as well as several red crystalline forms.

·         Selenium is most commonly produced from selenide in many sulfide ores, such as those of copper, silver, or lead. It is obtained as a byproduct of the processing of these ores, from the anode mud of copper refineries and the mud from the lead chambers of sulfuric acid plants.

·         Selenium may help prevent cancer by acting as an antioxidant or by enhancing immune activity. Not all studies agree on the cancer-fighting effects of selenium

 

Bromine (Br)

·         Bromine is a red volatile liquid at standard room temperature which has a reactivity between chlorine and iodine. Bromine is the only liquid nonmetallic element at room temperature and one of five elements on the period table that are liquid at or close to room temperature. The pure chemical element has the physical form of a diatomic molecule, Br2.

·         This element is corrosive to human tissue in a liquid state and its vapors irritate eyes and throat. Bromine vapors are very toxic upon inhalation.

·         Elemental bromine is used to manufacture a wide variety of bromine compounds used in industry and agriculture.

·         Bromine occurs in nature as bromide salts in very diffuse amounts in crustal rock. Due to leaching, bromide salts have accumulated in sea water and may be economically recovered from brine wells and the Dead Sea

 

Krypton (Kr)

·         A colorless noble gas, krypton occurs in trace amounts in the atmosphere, is isolated by fractionating liquefied air, and is often used with other rare gases in fluorescent lamps. Krypton is inert for most practical purposes but it is known to form compounds with fluorine.

·         Krypton was discovered in Great Britain, 1898 in residue left from evaporating nearly all components of liquid air

 

 

Technetium (Te)

·         Technetium has 22 isotopes, all of which are radioactive. It is one of two elements with Z < 83 that have no stable isotopes; the other element is promethium.

·         Technetium was the first element to be produced artificially. Since its discovery, searches for the element in terrestrial material have been made.  Finally in 1962, technetium-99 was isolated and identified in African pitchblende (a uranium rich ore) in extremely minute quantities as a spontaneous fission product of uranium-238.  If it does exist, the concentration must be very small.

·         The most useful isotope of technetium is 99Tcm (T1/2 = 6 hours) is used in many medical radioactive isotope tests because of its half-life being short, the energy of the gamma ray it emits, and the ability of technetium to be chemically bound to many biologically active molecules. Because 99Tc is produced as a fission product from the fission of uranium in nuclear reactors, large quantities have been produced over the years.

 

Rubidium (Ru)

·         Rubidium is a silver metal which is fairly commonly found in minerals.  The element is much more abundant than was thought several years ago. The most important use for rubidium has been in research and development, primarily in chemical and electronic applications

 

Platinum (Pt) group

·         Platinum occurs natively, accompanied by small quantities of iridium, osmium, palladium, ruthenium, and rhodium, all belonging to the same group of metals.

·         These are found in the alluvial deposits of the Ural mountains, of Columbia, and of certain western American states. Sperrylite, occurring with the nickel-bearing deposits of Sudbury, Ontario, is the source of a considerable amount of metal. The large production of nickel makes up for the fact that is only one part of the platinum metals in two million parts of ore.

·         Rhodium is the most expensive precious metal. Rhodium's primary use is as an alloying agent to harden platinum and palladium.

 

 

Metals

·         Most metals are not found in the Earth's crust in an elemental state, but as oxides or sulfides, called ores.

·         Metals are extracted from ores by removing the oxygen by combining it with a preferred chemical partner such as carbon, known as smelting.

  • Smelting makes use of a chemical reducing agent, commonly a fuel that is a source of carbon such as coke or charcoal, to remove oxygen, producing carbon dioxide and carbon monoxide. As most ores are impure, it is often necessary to use flux, such as limestone to remove the accompanying rock gangue as slag.

·         Copper melts at just over 1000 °C, while tin melts around 250 °C. Steel melts at around 1370 °C.

·         The five ferromagnetic elements are: Iron, Cobalt, Nickel, Dysprosium, and Gadolinium

·         History of Metalworking

 

 

Hydrocarbons

·         Hydrocarbons are any chemical compound that consists only of the elements carbon and hydrogen. Most hydrocarbons are combustible and thus used for energy production.

·         Liquid geologically-extracted hydrocarbons are referred to as petroleum (literally "rock oil") or mineral oil, while gaseous geologic hydrocarbons are referred to as natural gas.

·         The simplest hydrocarbon is methane (swamp/marsh gas): CH4. Ethane is C2H6. Propane is C3H8 and butane is C4H10.

 

Petroleum

 

Bitumen

·         Bitumen is a black, sticky liquid made up of polycyclic aromatic hydrocarbons.

·         Bitumen is obtained by fractional distillation of crude oil, the heaviest or bottommost fraction, but naturally-occurring deposits also occur.

·         Bituminous rocks are sedimentary rocks, usually shale, sandstone, or limestone, that contain traces of tar, bitumen, asphalt, petroleum or carbon.

·         Asphalt is a mixture of mineral aggregate and bitumen (tarmac in common parlance).

·         Tar refers to a black viscous material obtained from the destructive distillation of organic matter. Most tar is produced from coal as a byproduct of coke production, but it can also be produced from petroleum, peat or wood

·         Bitumen is primarily used for paving roads. Its other uses are for general waterproofing products, including roofing felt and for sealing flat roofs.

·         Bitumen is also the prime feed stock for petroleum production from tar sands currently under development in Alberta, Canada.

·         Naturally occurring deposits of bitumen are formed from the remains of ancient, microscopic algae which under heat and pressure of burial deep in the earth, the remains were transformed into materials such as bitumen, kerogen, or petroleum.

·         Bitumen can now be made from non-petroleum based renewable resources such as sugar, molasses and rice, corn and potato starches etc.

 

Charcoal

·         Charcoal is the blackish residue consisting of carbon obtained by burning wood (or animal substances) in the absence of oxygen.

·         Production of wood charcoal dates to antiquity, and generally consists of piling billets of wood on their ends so as to form a conical pile, openings being left at the bottom to admit air, with a central shaft to serve as a flue. The whole pile is covered with turf or moistened clay. The firing is begun at the bottom of the flue, and gradually spreads outwards and upwards.

·         Historically the massive production of charcoal has been a major cause of deforestation in Europe

·         Charcoals most common use is as a fuel, which burns hotter and cleaner than wood.  When plain wood is burned there is a large quantity of water driven off, plus assorted volatiles, and this limits the temperature of the fire. Burning charcoal, on the other hand, produces a much higher fire temperature (well over 1000oC), with little smoke. Thus it has used in metallurgy, cooking, and other industrial operations.

·         Copper were first smelted with charcoal in about 3000 BC, initiating the Bronze Age. All metal production until about 1700 was based on the use of charcoal. However, as metal production increased, deforestation became a significant problem throughout Europe, and attempts were made to find an alternative to charcoal. Around 1709, the English iron worker Abraham Darby found a way of making cast iron using coke, produced from plentiful bituminous coal. As a result of this innovation, demand for charcoal fell substantially, but it continued to be produced on a small scale, mainly for cooking.

·         One of the most important historical applications of charcoal is as a constituent of gunpowder.

·         It is also used in art as drawing crayons; but the greatest amount is used as. Charcoal is often used by blacksmiths, for cooking, and for other industrial applications. It was first used more than 30,000 years ago to make some of the earliest cave paintings.

·         Charcoal is used as an adsorbent to remove contaminants in respirators and air-conditioning systems (and previously gas-masks), as well from drinking water and automobile emissions.

·         Other forms of impure non-crystalline carbon include coke and soot

 

Coke

·         Coke is residue derived from burning bituminous coal in the absence of oxygen.

·         Since the smoke-producing constituents are driven off during the coking of the coal, coke forms a desirable fuel for furnaces in which conditions are not suitable for burning coal itself, for instance brewing or smelting where impurities would be transferred, or where higher heats are needed.

 

Paraffin

·         Paraffin is a common name for a group of alkane hydrocarbons with the general formula CnH2n+2, where n is greater than about 20, discovered by Carl Reichenbach. It is distinct from the fuel known in Britain as paraffin oil or just paraffin, which is called kerosene in American English. The solid forms of paraffin are called paraffin wax. It is used for candlemaking as well as many coatings.

 

 

Plastics & Polymers

·         Plastics are mostly synthetic polymers: long chains of atoms bonded to one another in repeating molecular units, or "monomers".

·         The vast majority of plastics are composed of polymers of carbon alone or with oxygen, nitrogen, chlorine or sulfur in the backbone. To customize the properties of a plastic, different molecular groups "hang" from the backbone

·         People experimented with plastics based on natural polymers for centuries. In the nineteenth century they discovered plastics based on chemically modified natural polymers: Charles Goodyear discovered vulcanization of rubber (1839) and Alexander Parkes discovered cellulose-based plastics in the 1860s.

·         The development of plastics has come from the use of natural materials (e.g., shellac) to the use of chemically modified natural materials (e.g., natural rubber, nitrocellulose) and finally to completely manmade molecules (e.g., epoxy, polyvinyl chloride, polyethylene).

Rubber

·         1736 Rubber is made from tree sap in Brazil. By the early 1800s natural rubber, tapped from rubber trees, was in widespread use.

·         The rubber tree’s sap-like extract (known as latex) is collected as the primary source of natural rubber. The Pará rubber tree initially grew only in Amazonia. In 1873 an attempt was made to grow rubber outside Brazil at the Royal Botanic Gardens, Kew.  In 1876 seedlings were sent to Ceylon and Singapore. Thereafter rubber was extensively propagated in the British colonies. By 1898, a rubber plantation had been established in Malaya, and today most rubber tree plantations are in Southeast Asia and some also in tropical Africa. Efforts to cultivate the tree in its native South America were unsatisfactory.

·         Natural rubber was sensitive to temperature, becoming sticky and smelly in hot weather and brittle in cold weather. In 1834, two inventors, Friedrich Ludersdorf of Germany and Nathaniel Hayward of the U.S., independently discovered that adding sulfur to raw rubber helped prevent the material from becoming sticky.

·         In 1839, the American inventor Charles Goodyear was experimenting with the sulfur treatment of natural rubber when, according to legend, he dropped a piece of sulfur-treated rubber on a stove. The rubber seemed to have improved properties; Goodyear followed up with further experiments, and developed a process known as "vulcanization" that involved cooking the rubber with sulfur. Compared to untreated natural rubber, Goodyear's "vulcanized rubber" was stronger, more resistant to abrasion, more elastic, much less sensitive to temperature, impermeable to gases, and highly resistant to chemicals and electric current.

·         The first synthetic rubber polymer was obtained by Lebedev in 1910. In 1931 one of the first successful synthetic rubbers, known as "neoprene", was developed at DuPont. Neoprene is highly resistant to heat and chemicals such as oil and gasoline, and is used in fuel hoses and as an insulating material in machinery.

o        Worldwide natural rubber supplies were limited and by mid-1942 most of the rubber-producing regions were under Japanese control. In 1935, German chemists synthesized the first of a series of synthetic rubbers known as "Buna rubbers". One such Buna rubber became the basis for U.S. synthetic rubber production during World War II.

Celluloid

·         Englishman Alexander Parkes developed a "synthetic ivory" named "pyroxlin", which he marketed under the trade name "Parkesine", which was made from cellulose treated with nitric acid and a solvent. However, Parkes was not able to scale up the process to an industrial level, and products made from Parkesine quickly warped and cracked after a short period of use.

·         An American printer and amateur inventor named John Wesley Hyatt took up where Parkes left off. Parkes had failed for lack of a proper softener, but Hyatt discovered that camphor would do the job very nicely. Since cellulose was the main constituent used in the synthesis of his new material, Hyatt named it "celluloid" in 1863.

·         Celluloid's real breakthrough products were waterproof shirt collars, cuffs, and the false shirtfronts known as "dickies". Celluloid proved a cheap and attractive replacement for ivory, tortoiseshell, and bone. Hyatt figured out how to fabricate the material in a strip format for movie film and by 1900 movie film was a major market for celluloid.

·         Cellulose-based fabric was developed in 1899 in France and became well known under the trade name "rayon", and was produced in great quantities through the 1930s, when it was supplanted by better artificial fabrics. It could also be produced in a transparent sheet form known as "cellophane".

Synthetic Polymers

·         Plastic can be classified by their polymer backbone (poly(vinyl chloride), polyethylene, poly(methyl methacrylate)and other acrylics, silicones, polyurethanes, polyesters, polystyrene, polypropylene, polyamides (nylons)

·         Today there are primarily six commodity polymers in use, namely polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polystyrene and polycarbonate. These make up nearly 98% of all polymers and plastics encountered in daily life.

·         1907 The first plastic based on a synthetic polymer (“Bakelite”) invented by New York chemist Leo Baekeland by mixing a disinfectant (carbolic acid) with a preservative (formaldehyde)

o        Baekeland was searching for an insulating shellac to coat wires in electric motors and generators. Baekeland found that mixtures of phenol and formaldehyde (HCOH) formed a sticky mass when mixed together and heated, and the mass became extremely hard if allowed to cool and dry. He continued his investigations and found that the material could be mixed with wood flour, asbestos, or slate dust to create "composite" materials with different properties. Most of these compositions were strong and fire resistant. The only problem was that the material tended to foam during synthesis, and the resulting product was of unacceptable quality. Baekeland built pressure vessels to force out the bubbles and provide a smooth, uniform product.

o        Bakelite was the first true plastic. It was a purely synthetic material, not based on any material or even molecule found in nature. It was also the first "thermoset" plastic. Conventional "thermoplastics" can be molded and then melted again, but thermoset plastics form bonds between polymers strands when "cured", creating a tangled matrix that cannot be undone without destroying the plastic. Thermoset plastics are tough and temperature resistant.

o        Bakelite was cheap, strong, and durable. It was molded into thousands of forms, such as radios, telephones, clocks, and, of course, billiard balls. The U.S. government even considered making one-cent coins out of it when World War II caused a copper shortage. Phenolic plastics have been largely replaced by cheaper and less brittle plastics, but they are still used in applications requiring its insulating and heat-resistant properties

·         After the First World War, improvements in chemical technology led to an explosion in new forms of plastics. Among the earliest examples in the wave of new plastics were "polystyrene" (PS) and "polyvinyl chloride" (PVC), developed by IG Farben of Germany. Polystrene is used to make Styrofoam cups.

·         "Polyamide" (PA), far better known by its trade name, "nylon" was the first purely synthetic fiber, developed by the Du Pont Corporation in 1935. It was first used commercially in a toothbrush (1938), followed more famously by women's “nylons” stockings (1940), then extensively in military supplies during World War II. It is made of repeating units linked by peptide bonds (another name for amide bonds) and is frequently referred to as polyamide (PA). Nylon was the first commercially successful polymer and the first synthetic fiber to be made entirely from coal, water and air. These are formed into monomers of intermediate molecular weight, which are then reacted to form long polymer chains

·         By 1936, American, British, and German companies were producing polymethyl methacrylate (PMMA), better known as "acrylic". Although acrylics are now well known for their use in paints and synthetic fibers, such as "fake furs", in their bulk form they are actually very hard and more transparent than glass, and are sold as glass replacements under trade names such as "Plexiglas" and "Lucite".

·         "Polyethylene" (PE), sometimes known as "polythene", was discovered in 1933 at the British Imperial Chemical Industries (ICI). It is used to make films and packaging materials, containers, plumbing, and automotive fittings.

·         Polyethylene would lead after the war to an improved material, "polypropylene" (PP), which was discovered in the early 1950s. Polypropylene is similar to its ancestor, polyethylene, and shares polyethylene's low cost, but it is much more robust. It is used in everything from plastic bottles to carpets to plastic furniture, and is very heavily used in automobiles.

·         Polyurethane was invented by Friedrich Bayer & Company in 1937, and would come into use after the war, in blown form for mattresses, furniture padding, and thermal insulation. It is also one of the components (in non-blown form) of the fiber spandex.

·         In 1939, IG Farben filed a patent for "polyepoxide" or "epoxy". Epoxies are a class of thermoset plastic that form cross-links and "cure" when a catalyzing agent, or "hardener", is added. After the war they would come into wide use for coatings, "adhesives", and composite materials. Fiberglass is now often used to build sport boats, and carbon-epoxy composites are an increasingly important structural element in aircraft, as they are lightweight, strong, and heat resistant.

·         Two English chemists developed "polyethylene terephthalate" (PET or PETE) in 1941, and it would be used for synthetic fibers in the postwar era, with names such as "polyester", "dacron", and "terylene" and is a popular material for making bottles for soft drinks.

·         One of the most impressive plastics used in the war, and a top secret, was "polytetrafluoroethylene" (PTFE), better known as "Teflon", which could be deposited on metal surfaces as a scratchproof and corrosion-resistant, low-friction protective coating. A Du Pont chemist discovered Teflon by accident in 1938. During the war, it was used in gaseous-diffusion processes to refine uranium for the atomic bomb, as the process was highly corrosive. By the early 1960s, Teflon "nonstick" frying pans were a hot item. Teflon was later used to synthesize the breathable fabric "Gore-Tex", which can be used to build raingear that in principle "breathes" to keep the wearer's moisture from building up. GoreTex is also used for surgical implants; Teflon strand is used to make dental floss; and Teflon mixed with fluorine compounds is used to make "decoy" flares dropped by aircraft to distract heat-seeking missiles.

·         After the war, the new plastics that had been developed entered the consumer mainstream in a flood. New manufacturing were developed, using various forming, molding, casting, and extrusion processes, to churn out plastic products in vast quantities. American consumers enthusiastically adopted the endless range of colorful, cheap, and durable plastic gimmicks being produced for new suburban home life.

·         One of the most visible parts of this plastics invasion was Earl Tupper's "Tupperware", a complete line of sealable polyethylene food containers that Tupper cleverly promoted through a network of housewives who sold Tupperware as a means of bringing in some money. The Tupperware line of products was well thought out and highly effective, greatly reducing spoilage of foods in storage. Thin-film "plastic wrap" that could be purchased in rolls also helped keep food fresh.

·         Another prominent element in 1950s homes was "Formica", a plastic laminate that was used to surface furniture and cabinetry. Formica was durable and attractive. It was particularly useful in kitchens, as it did not absorb, and could be easily cleaned of stains from food preparation, such as blood or grease. With Formica, a very attractive and well-built table could be built using low-cost and lightweight plywood with Formica covering, rather than expensive and heavy hardwoods like oak or mahogany.

·         Composite materials like fiberglass came into use for building boats and, in some cases, cars. Polyurethane foam was used to fill mattresses, and Styrofoam was used to line ice coolers and make float toys.

·         Plastics continue to be improved. General Electric introduced "lexan", a high-impact "polycarbonate" plastic, in the 1970s. Du Pont developed "Kevlar", an extremely strong synthetic fiber that was best known for its use in bullet-proof vests and combat helmets. Kevlar was so remarkable that Du Pont officials actually had to release statements to deny rumors that the company had received the recipe for it from space aliens.

·         Plastics are durable and degrade very slowly. In some cases, burning plastic can release toxic fumes. Also, the manufacturing of plastics often creates large quantities of chemical pollutants. By the 1990s, plastic recycling programs were common in the United States and elsewhere.

·         Thermoplastics can be remelted and reused, and thermoset plastics can be ground up and used as filler, though the purity of the material tends to degrade with each reuse cycle. There are methods by which plastics can be broken back down to a feedstock state.

·         Unfortunately, recycling plastics has proven difficult. The biggest problem with plastic recycling is that it is difficult to automate the sorting of plastic waste, and so it is labor intensive. To assist recycling of disposable items, the Plastic Bottle Institute of the Society of the Plastics Industry devised a now-familiar scheme to mark plastic bottles by plastic type. A recyclable plastic container using this scheme is marked with a triangle of three "chasing arrows", which enclose a number giving the plastic type

·         Research has been done on biodegradable plastics that break down with exposure to sunlight. Starch can be mixed with plastic to allow it to degrade more easily, but it still does not lead to complete breakdown of the plastic. Some researchers have actually genetically engineered bacteria that synthesize a completely biodegradable plastic, but this material is expensive at present. BASF make Ecoflex, a fully biodegradable polyester for food packaging applications. The disadvantage of biodegradable plastics is that the carbon that is locked up in them is released into the atmosphere as the greenhouse gas carbon dioxide when they degrade, though if they are made from organic material there is no net gain in emissions. So far, these plastics have proven too costly and limited for general use, and critics have pointed out that the only real problem they address is roadside litter, which is regarded as a secondary issue. When such plastic materials are dumped into landfills, they can become "mummified" and persist for decades even if they are supposed to be biodegradable. It is also possible that bacteria will eventually develop the ability to degrade plastics. This has already happened with nylon: two types of nylon eating bacteria, Flavobacteria and Pseudomonas, were found in 1975 to possess enzymes (nylonase) capable of breaking down nylon.

 

Element Formation

Nucleosynthesis

·         Nucleosynthesis is the process of creating new atomic nuclei from preexisting nucleons (protons and neutrons). The primordial preexisting nucleons were formed from the quark-gluon plasma of the Big Bang as it cooled below ten million degrees, called nucleogenesis, the genesis of nucleons in the universe. The subsequent nucleosynthesis of the elements occurs primarily either by nuclear fusion or nuclear fission.

·         The types of nucleosynthesis known of are: big bang, stellar, and explosive nucleosyntheses, and cosmic ray spallation

 

Big Bang Nucleosynthesis

·         Occurred within the first three minutes of the universe is responsible for much of the abundance ratios of 1H (protium), 2H (deuterium), helium-3 (3He), and helium-4 (4He), in the universe.

·         Although 4He continues to be produced by other mechanisms (such as stellar fusion and alpha decay) and trace amounts of 1H continue to be produced by spallation and certain types of radioactive decay (proton emission and neutron decay), most of the mass of these isotopes in the universe, and all but the insignificant traces of the 3He and deuterium in the universe produced by rare processes such as cluster decay, are thought to have been produced in the Big Bang.

·         The nuclei of these elements, along with some 7Li, are believed to have been formed when the universe was between 100 and 300 seconds old, after the primordial quark-gluon plasma froze out to form protons and neutrons. Because of the very short period in which Big Bang nucleosynthesis occurred before being stopped by expansion and cooling, no elements heavier than lithium could be formed. (Elements formed during this time were in the plasma state, and did not cool to the state of neutral atoms until much later).

 

Stellar Nucleosynthesis

·         Stellar nucleosynthesis are nuclear reactions taking place in stars to build the nuclei of the heavier elements. . It is responsible for generation of elements between helium and iron by nuclear fusion

·         The processes involved began to be understood early in the twentieth century, when it was first realized that the energy released from nuclear reactions accounted for the longevity of the Sun as a source of heat and light. The prime energy producer in the sun is the fusion of hydrogen to helium, which occurs at a minimum temperature of 3 million kelvins.

·         Arthur Stanley Eddington first suggested in 1920 that stars obtain their energy by fusing hydrogen to helium, but this idea was not generally accepted because it lacked hard calculations for the conditions in stellar cores. Hans Bethe first gave a quantitative description of this process in the years immediately before World War II. Fred Hoyle's original work on nucleosynthesis of heavier elements in stars (including a detailed mechanistic analysis for the production of carbon) occurred just after World War II, but this work was in search of a way to produce heavier elements from hydrogen in stars, in the steady state model of cosmology. Subsequently, Hoyle's picture was expanded by creative contributions

·         The successive nuclear fusion processes which occur inside stars are known as hydrogen burning, helium burning, carbon burning, neon burning, oxygen burning and silicon burning. These processes are able to create elements up to iron and nickel.

·         Of particular importance is carbon, because its formation from He is a bottleneck in the entire process. Carbon is also the main element used in the production of free neutrons within the stars, giving rise to the s process which involves the slow absorption of neutrons to produce elements heavier than iron and nickel (56Fe and 62Ni).

·         Heavier elements can be assembled within stars by a neutron capture process known as the s process or in explosive environments, such as supernovae, by a number of processes.

·         The products of stellar nucleosynthesis are generally distributed into the universe as planetary nebulae or through the solar wind

 

Explosive nucleosynthesis

·         Including supernova nucleosynthesis, produces most of the heavy elements present in the universe. In explosive environments such as supernovae further nucleosynthesis processes can occur, such as the r process (in which elements heavier than iron and nickel are produced by rapid absorption of free neutrons) and the rp process (which involves the rapid absorption of free protons).

 

Cosmic ray spallation

·         Produces some of the lightest elements present in the universe (though not significant deuterium). Most notably spallation is believed to be responsible for the generation of all or almost all of 3He and the elements lithium, beryllium and boron. This process results from the impact of cosmic rays against the interstellar medium, fragmenting carbon, nitrogen and oxygen nuclei present in the cosmic rays. Note that Be and B are not significantly produced in stellar fusion processes, because the instability of any 8Be formed from two 4He nuclei prevents simple 2-particle reaction building-up of these elements.

 

Chemical Analysis

 

Electrolysis

·         An ionic compound is dissolved with an appropriate solvent so that its ions are available in the liquid. An electrical current is applied between a pair of inert electrodes immersed in the liquid. The negatively charged electrode (cathode) and the positively charged one (anode) each attract ions of the opposite charge.

·         Sir Humpry Davy used electrolysis in 1808-1809 to discover several elements.  Michael Faraday, initially his assistant, stated several laws of electrolysis

·         It is important in the industrial manufacture of aluminum, lithium, sodium, potassium, chlorine, and aspirin. One important use of electrolysis is to produce hydrogen to be used as an energy carrier from the electrolysis of water. However the energy efficiency of this is 25-40%

·         Gel electrophoresis is an electrolysis where the solvent is a gel: it is used to separate substances, such as DNA strands, based on their electrical charge.

 

Spectroscopy

·         Spectroscopy is the study of matter by investigating light, sound, or particles that are emitted, absorbed or scattered by the matter under investigation.

·         Historically, spectroscopy referred to studies in which visible light was used on matter and for qualitative and quantitative analyses. Recently, however, new techniques have been developed that utilize not only visible light, but many other forms of electromagnetic and non-electromagnetic radiation: microwaves, radiowaves, x-rays, electrons, phonons (sound waves) and others. It is often used in analytical chemistry for the identification of substances through the spectrum emitted from them or absorbed in them.

·         The three main types of spectroscopy are emission, absorption, and scatttering

·         In 1853 Anders Jonas Ångström a Swedish physicist presented theories about gases having spectra and fundamental principles of spectrum analysis.

·         In 1854, David Alter of Pennsylvania published the first scientific work that included the spectral radiance properties for twelve metals. He began studying the optical properties of matter ever since finding a piece of melted, prismatic glass in the debris of the great Pittsburgh fire of 1845. By 1855, Alter published another article that expanded his original theory by including six gases.

·         In 1860, German physicist Gustav Kirchoff and chemist Robert Bunsen published their own findings on the spectra of eight metals and identified these metals in natural elements. Kirchoff went on to contribute fundamental research on the nature of spectral absorption. Spectrum analysis was then grouped by Kirchoff into the three fundamental laws commonly called Kirchoff's Laws, these laws integrated both Alter and Angstrom's discoveries of radiance and emission with Kirchoff's fundamental discoveries of absorption

·         The mass-to-charge ratios of molecules and atoms are studied in mass spectrometry, sometimes called mass spectroscopy. Mass spectrometry is more of a measuring technique (metric) than an observation (scopic) technique but can produce a spectrum of masses, a mass spectrum, similar in appearance to other spectroscopy techniques.

 

 

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