Arsenic (33)

Arsenic and its compounds are poisonous as any reader of "who-done-it" books knows. Upon heating arsenic and some minerals containing arsenic, it sublimes (transfers from the solid to the gaseous state, without passing through the liquid state).

•Name: Arsenic
•Symbol: As
•Atomic number: 33
•Atomic weight: 74.92160
•Standard state: solid at 298 K
•CAS Registry ID: 7440-38-2
•Group in periodic table: 15
•Group name: Pnictogen
•Period in periodic table: 4
•Block in periodic table: p-block
•Color: metallic grey
•Classification: Semi-metallic

Historical information

Arsenic was discovered by Known since ancient times at no data in not known. Origin of name is from the Greek word "arsenikon" meaning "yellow orpiment". Arsenic compounds were mined by the early Chinese, Greek and Egyptian civilizations. No doubt they discovered its toxic properties early on.

It is believed that Albertus Magnus obtained the element in 1250 A.D. who obtained it by heating soap together with orpiment (arsenic trisulphide, As2S3).

Arsenic is one of the elements which has an alchemical symbol (alchemy is an ancient pursuit concerned with, for instance the transformation of other metals into gold), which is two circles joined by a line.

Physical properties

•Melting point: 1090 [or 817 °C (1503 °F)] (under pressure) K
•Boiling point: 887 [or 614 °C (1137 °F)] (sublimes) K
•Density of solid: 5727 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d10.4s2.4p3
•Shell structure: 2.8.18.5
•Term symbol: 4S3/2

Isolation

It is not usually necessary to make arsenic in the laboratory as it is commercially available. Arsenic is found in nature in a number of minerals including realgar (As4S4), orpiment (As2S3), arsenolite (As2O3), and iron minerals such as arsenopyrite (FeAsS) and loellingite (FeAs2). Arsenic is made on an industrial scale by heating appropriate minerals in the absence of air. The arsenic is condensed out as a solid.

FeAsS (700°C) → FeS + As(g) → As(s)

Interesting Facts about Arsenic:

•Arsenic (English/French) Arsen (German) Arsenico (Italian) Arsénico (Spanish) Arsenik (Swedish)

•Arsenic is found naturally in a common mineral called Arsenopyrite or Mispickel (FeSAs). It is also found in arsenides of metals such as silver, cobalt and nickel. Apart from these inorganic forms, arsenic is found in food, water and air also.

•Arsenic is located in the Groups 13,14,15,16 and 17 of the Periodic Table and hence, is classified as a metalloid element. Thus, it has the properties of both metals and non-metals.

•The most common grey arsenic has a metallic sheen and conducts electricity. Yellow arsenic is metastable, a poor electrical conductor and does not have a metallic sheen. Black arsenic is glassy, brittle and a poor electrical conductor.

•Due to its high level of toxicity, arsenic has been named as the ‘Kings of Poison’. Hence, for the same reason, it is used as a wood preservative against insects, bacteria and fungi. It also finds its use in making insecticides, poison, weed killers, etc.

•Arsenic, in the form of Gallium arsenide, is used in lasers that are employed to convert electricity into coherent light.

•Arsenic is used in ammunition manufacturing, since it helps to create harder and rounder bullets.

•The top producers of arsenic are China, Peru, Chile and Morocco. While the production from Peru comes from copper mining, production in China comes from mining of gold.

•Pure arsenic is less dangerous than arsenic compounds, such as AsH3 and As2O3, which are absorbed easily and are carcinogenic with high toxicity.

•In the 18th, 19th and 20th century, arsenic was used in the form of medicines, two most common being arsphenamine and arsenic trioxide. While the former medication was prescribed for syphilis and trypanosomiasis, the latter one was useful in treating cancer.

•Some of the side effects of arsenic include agitation, constipation, darkening of skin, drowsiness, earache, poor appetite, increased sweating, mouth sores, fatigue, weight loss, nausea, nose bleeding, vomiting, depression, seizures, tremors, dry eyes, allergic reactions, sudden weight gain, wheezing, irregular pulse and increased thirst.

Gallium (31)

Gallium is the only metal, except for mercury, cesium, and rubidium, which can be liquid near room temperatures; this makes possible its use in high-temperature thermometers. It has one of the longest liquid ranges of any metal and has a low vapor pressure even at high temperatures.

Ultra-pure gallium has a beautiful, silvery appearance, and the solid metal exhibits a conchoidal fracture similar to glass. The metal expands on solidifying; therefore, it should not be stored in glass or metal containers, as they may break as the metal solidifies.

•Name: Gallium
•Symbol: Ga
•Atomic number: 31
•Atomic weight: 69.723 
•Standard state: solid at 298 K (but melts only slightly above this temperature)
•CAS Registry ID: 7440-55-3
•Group in periodic table: 13
•Period in periodic table: 4
•Block in periodic table: p-block
•Color: silvery white
•Classification: Metallic

Historical information

Gallium was discovered by Paul-Emile Lecoq de Boisbaudran at 1875 in France. Origin of name is from the Latin word "Gallia" meaning "France" and perhaps also from the Latin word "gallus" (the cock, a translation of Lecoq, the discoveror of gallium). Gallium was an element whose existence was predicted by Mendeleev in 1871. He predicted that the then unknown element gallium should resemble aluminum in its properties. He suggested therefore the name eka-aluminium (symbol Ea). His predictions for the properties of gallium are remarkably close to the reality. Gallium was discovered spectroscopically by Paul-Emile Lecoq de Boisbaudran in 1875, who in the same year obtained the free metal by electrolysis of a solution of the hydroxide Ga(OH)3 in KOH.

Physical properties

•Melting point: 302.91 [or 29.76 °C (85.57 °F)] K
•Boiling point: 2477 [or 2204 °C (3999 °F)] K

Orbital properties

•Ground state electron configuration: [Ar].3d10.4s2.4p1
•Shell structure: 2.8.18.3
•Term symbol: 2P1/2

Isolation

Gallium is normally a byproduct of the manufacture of aluminum. The purification of bauxite by the Bayer process results in concentration of gallium in the alkaline solutions from an aluminum:gallum ratio from 5000 to 300. Electrolysis using a mercury electrode gives a further concentration and further electrolysis using a stainless steel cathode of the resulting sodium gallate affords liquid gallium metal.

Very pure gallium requires a number of further processes ending with zone refining to make very pure gallium metal.

Interesting Facts:

Gallium (English, French, German, Swedish) Gallio (Italian) Galio (Spanish)

Low melting gallium alloys are used in some medical thermometers as non-toxic substitutes for mercury.

Gallium arsenide is used in semiconductor production mainly for laser diodes, light-emitting diodes and solar panels. It is also used to create brilliant mirrors.

Gallium has the second largest liquid range of any element and is one of the few metals that is liquid near room temperature (m.pt. 29.76 oC, 85.6 oF ), melting in the hand.

The other metals with this property are cesium, francium and mercury.

Bromine is the only non-metallic element that is liquid at or around room-temperature.

Gallium liquid clings to or wets glass and similar surfaces.

Gallium also has the unusual property that (like water) it expands as it freezes.

Four other elements expand when they freeze: silicon, bismuth, antimony and germanium

29^th:
GERMANIUM (32)

Germanium is a gray-white semi-metal, and in its pure state is crystalline and brittle, retaining its luster in air at room temperature. It is a very important semiconductor material. Zone-refining techniques have led to production of crystalline germanium for semiconductor use with an impurity of only one part in 10-10.

Certain germanium compounds have a low mammalian toxicity, but a clear activity against certain bacteria, which makes them of interest as chemotherapeutic agents.

•Name: Germanium
•Symbol: Ge
•Atomic number: 32
•Atomic weight: 72.64
•Standard state: solid at 298 K
•CAS Registry ID: 7440-56-4
•Group in periodic table: 14
•Period in periodic table: 4
•Block in periodic table: p-block
•Color: greyish white
•Classification: Semi-metallic

Historical information

Germanium was discovered by Clemens Winkler at 1886 in Germany. Origin of name is from the Latin word "Germania" meaning "Germany". Germanium was an element whose existence was predicted by Mendeleev in 1871. He predicted that the then unknown element germanium should resemble silicon in its properties. He suggested therefore the name ekasilicon (symbol Es). His predictions for the properties of germanium are remarkably close to the reality. Germanium was discovered in a mineral called argyrodite by Clemens Alexander Winkler in 1886.

Physical properties

•Melting point: 1211.4 [or 938.3 °C (1720.9 °F)] K
•Boiling point: 3093 [or 2820 °C (5108 °F)] K
•Density of solid: 5323 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d10.4s2.4p2
•Shell structure: 2.8.18.4
•Term symbol: 3P0

Isolation

There is normally no need to make germanium in the laboratory as it is readily available commercially. Germanium is available through the treatment of germanium dioxide, GeO2, with carbon or hydrogen. The extraction of germanium from flue dust is complex because of the difficulty in separating it from zinc, which is also present.

GeO2 + 2C → Ge + 2CO

GeO2 + 2H2 → Ge + 2H2O

Very pure germanium can be made by the reaction of GeCl4 with hydrogen.

GeCl4 + 2H2 → Ge + 4HCl

Interesting Facts about Germanium:

Germanium (English, French, German, Swedish)  Germanio (Italian/Spanish)

Trace impurities can be added to germanium to produce semiconductors.

Germanium and germanium oxide are transparent to infrared light and exhibit other desirable optical properties, so the element is used in infrared spectrometers and lenses.

Elemental arsenic occurs in two solid modifications: yellow, and grey or metallic, with specific gravities of 1.97, and 5.73, respectively. The element is a steel grey, very brittle, crystalline, semi metallic (metalloid) solid. It tarnishes in air, and when heated rapidly oxidizes to arsenous oxide which has a garlic odor.

Zinc (30)

Zinc-deficient animals require 50% more food to gain the same weight of an animal supplied with adequate amounts of zinc. Zinc is not particularly toxic and is an essential element in the growth of all animals and plants.

Plating thin layers of zinc on to iron or steel is known as galvanizing and helps to protect the iron from corrosion.

•Name: Zinc
•Symbol: Zn
•Atomic number: 30
•Atomic weight: 65.38
•Standard state: solid at 298 K
•CAS Registry ID: 7440-66-6
•Group in periodic table: 12
•Period in periodic table: 4
•Block in periodic table: d-block
•Color: bluish pale grey
•Classification: Metallic

Historical information

Zinc was discovered by Andreas Marggraf at 1746 in Germany. Origin of name is from the German word "zink". Centuries before zinc was recognized as a distinct element, zinc ores were used for making brass (a mixture of copper and zinc). A brass dating from between 1400-1000 BC has been found in Palestine. An alloy containing 87% zinc was found in prehistoric ruins in Transylvania. The smelting of zinc ores with copper was apparently discovered in Cyprus and was used later by the Romans. Metallic zinc was produced in the 13th century in India by reducing calamine (zinc carbonate, ZnCO3) with organic substances such as wool.

The metal was rediscovered later in Europe. William Champion set up a zinc industry in Bristol (England) in the 1740s. Other plants were established a little later in Belgium and Silesia.

Sometime prior to the autumn of 1803, the Englishman John Dalton was able to explain the results of some of his studies by assuming that matter is composed of atoms and that all samples of any given compound consist of the same combination of these atoms. Dalton also noted that in series of compounds, the ratios of the masses of the second element that combine with a given weight of the first element can be reduced to small whole numbers (the law of multiple proportions). This was further evidence for atoms. Dalton's theory of atoms was published by Thomas Thomson in the 3rd edition of his System of Chemistry in 1807 and in a paper about strontium oxalates published in the Philosophical Transactions. Dalton published these ideas himself in the following year in the New System of Chemical Philosophy. The symbol used by Dalton for zinc is a circle with a capital 'Z' inside.

Physical properties

•Melting point: 692.68 [or 419.53 °C (787.15 °F)] K
•Boiling point: 1180 [or 907 °C (1665 °F)] K
•Density of solid: 7140 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d10.4s2
•Shell structure: 2.8.18.2
•Term symbol: 1S0

Isolation

Zinc metal is readily available commercially so it is not normally necessary to make it in the laboratory. Most zinc production is based upon sulfide ores. These are roasted in industrial plants to form zinc oxide, ZnO. This may be reduced with carbon to form zinc metal, but in practice ingenious technology is required to ensure that the resulting zinc does not contain oxide impurities.

ZnO + C → Zn + CO

ZnO + CO → Zn + CO2

CO2 + C → 2CO

The other type of extraction is electrolytic. Dissolution of crude zinc oxide, ZnO, in sulphuric acid gives zinc sulphate, ZnSO4 in solution. Cadmium is an impurity and this is removed as a precipitate of cadmium sulphate by the addition of zinc dust. Electrolysis of the ZnSO4 solution using aluminum cathodes and lead alloyed with silver anodes gives pure zinc metal coated on the aluminum. Oxygen gas is liberated at the anode.

Very pure zinc may be formed from crude zinc by zone refining and single crystals can be grown with purities of better than 99.9999%.

Interesting Facts:

1. Zinc (English) Zinc (French) Zink (Deutsch) Zinco (Italian/Spanish) Zink (Swedish)

2. Zinc's use has been traced back over 2500 years. The earliest documented use was in ancient ornaments and decorations found in eastern countries. Alchemists also produced zinc oxide, which they called “philosophers wool.”

3. Over fifty countries produce zinc, the largest being China, which tops 3,500,000 tons per year! A majority of zinc mined comes from underground sources in the form of zinc ore. After being mined, it must undergo processing as it isn't pure enough to be smelted.

4. Most zinc produced is used in galvanizing. This process is usually used to protect iron or steel from corrosion. Its properties make it more reactive than surrounding metals, meaning the corrosion (usually rust) is attracted to the zinc. This makes the metals much more durable in harsh environments, reducing the need for periodic replacement.

5. Brass alloy contains 3% to 45% zinc, with the remainder being copper. Brass is used to form many common items such as: musical instruments, decorations, building hardware, and tools. Other common zinc alloys include nickel silver, electrical solder, and a lead substitute in water pipes.

6. Zinc can help you stay young! It is believed to have anti-oxidant properties, which keep our skin and muscles from aging. It is available in dietary supplements, as well as in many natural foods. There is also a belief that zinc can help to shorten the length of the common cold as a homeopathic treatment.

7. Although zinc is helpful in moderation, an excess is dangerous both to humans and to the environment. It can reduce the rate our bodies absorb copper and iron, and inhalation has shown to cause a symptom called the “zinc shakes”. Processing facilities have also been shown to increase the heavy metal content in bodies of water. Additionally, high zinc levels in the soil can rob plants of the ability to absorb nutrients.

8. Back to science. Zinc's atomic number is 30, meaning an atom has thirty protons in the nucleus. Its atomic weight is 35.38, and has a melting point of 787.1 degrees Fahrenheit. It has a shiny bluish-white color in its pure form and is hard and brittle.

9. Zinc can only be created by nuclear fusion from supernovas. When massive stars reach the end of their life, they can explode and erupt their contents into space. This is the primary source of most heavy elements in the universe.

Copper (29)

Copper is one of the most important metals. Copper is reddish with a bright metallic luster. It is malleable, ductile, and a good conductor of heat and electricity (second only to silver in electrical conductivity). Its alloys, brass and bronze, are very important. Monel and gun metals also contain copper. Apparently the reason that policemen in the USA are nicknamed "cops" or "coppers" is to do with their uniforms which used to have copper buttons.

The most important compounds are the oxide and the sulphate, (blue vitriol).

•Name: Copper
•Symbol: Cu
•Atomic number: 29
•Atomic weight: 63.546
•Standard state: solid at 298 K
•CAS Registry ID: 7440-50-8
•Group in periodic table: 11
•Group name: Coinage metal
•Period in periodic table: 4
•Block in periodic table: d-block
•Color: copper, metallic
•Classification: Metallic

Historical information

Copper was discovered by Known since ancient times at no data in not known. Origin of name is from the Latin word "cuprum" meaning the island of "Cyprus". The discovery of copper dates from prehistoric times. There are reports of copper beads dating back to 9000BC found in Iraq. Methods for refining copper from its ores were discovered around 5000BC and a 1000 or so years later it was being used in pottery in North Africa.

Part of the reason for it being used so early is simply that it is relatively easy to shape. However it is somewhat too soft for many tools and around 5000 years ago it was discovered that when copper is mixed with other metals the resulting alloys are harder than the copper itself. As examples, brass is a mixture of copper and zinc while bronze is a mixture of copper and tin.

Copper is one of the elements which has an alchemical symbol, what looks like the symbol for female.

Sometime prior to the autumn of 1803, the Englishman John Dalton was able to explain the results of some of his studies by assuming that matter is composed of atoms and that all samples of any given compound consist of the same combination of these atoms. Dalton also noted that in series of compounds, the ratios of the masses of the second element that combine with a given weight of the first element can be reduced to small whole numbers (the law of multiple proportions). This was further evidence for atoms. Dalton's theory of atoms was published by Thomas Thomson in the 3rd edition of his System of Chemistry in 1807 and in a paper about strontium oxalates published in the Philosophical Transactions. Dalton published these ideas himself in the following year in the New System of Chemical Philosophy.

Physical properties

•Melting point: 1357.77 [or 1084.62 °C (1984.32 °F)] K
•Boiling point: 3200 [or 2927 °C (5301 °F)] K
•Density of solid: 8920 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d10.4s1
•Shell structure: 2.8.18.1
•Term symbol: 2S1/2

Isolation

Copper metal is readily available commercially so it is not normally necessary to make it in the laboratory. Most copper production is based upon sulfide ores containing little copper but quite a lot of iron. New cleaner technologies are now important but older processes present major environmental problems. Complex procedures are used initially to form a form of copper sulfide appropriate for final reduction via a copper(I) oxide. The resulting crude copper is purified using an electrolytic procedure involving plating onto pure copper cathodes.

2Cu2S + 3O2 → 2Cu2O + 2SO2

2Cu2O + Cu2S → 6Cu + SO2

Notably, the purification step leaves an "anode slime" which contains useful amounts of silver and gold.

Nickel (28)

Nickel is found as a constituent in most meteorites and often serves as one of the criteria for distinguishing a meteorite from other minerals. Iron meteorites, or siderites, may contain iron alloyed with from 5 to nearly 20% nickel. The USA 5-cent coin (whose nickname is "nickel") contains just 25% nickel. Nickel is a silvery white metal that takes on a high polish. It is hard, malleable, ductile, somewhat ferromagnetic, and a fair conductor of heat and electricity.

Nickel carbonyl, [Ni(CO)4], is an extremely toxic gas and exposure should not exceed 0.007 mg M-3.

•Name: Nickel
•Symbol: Ni
•Atomic number: 28
•Atomic weight: 58.6934
•Standard state: solid at 298 K
•CAS Registry ID: 7440-02-0
•Group in periodic table: 10
•Period in periodic table: 4
•Block in periodic table: d-block
•Color: lustrous, metallic, silvery tinge
•Classification: Metallic

Historical information

Nickel was discovered by Axel Fredrik Cronstedt at 1751 in Sweden. Origin of name is from the German word "kupfernickel" meaning Devil's copper or St Nicholas's (Old Nick's) copper. Minerals containing nickel were of value for coloring glass green. The mineral used for coloring glass was called kupfernickel (false copper). Nickel was discovered by Baron Axel Frederik Cronstedt in 1751 in a mineral called niccolite. Apparently, he had expected to extract copper from this mineral but got none at all, obtaining instead a white metal that he called nickel after the mineral from which it was extracted.

Physical properties

•Melting point: 1728 [or 1455 °C (2651 °F)] K
•Boiling point: 3186 [or 2913 °C (5275 °F)] K
•Density of solid: 8908 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d8.4s2
•Shell structure: 2.8.16.2
•Term symbol: 3F4

Isolation

It is not normally necessary to make nickel in the laboratory as it is available readily commercially. Small amounts of pure nickel can be isolated in the laboratory through the purification of crude nickel with carbon monoxide. The intermediate in this process is the highly toxic nickel tetracarbonyl, Ni(CO)4. The carbonyl decomposes on heating to about 250°C to form pure nickel powder.

Ni + 4CO (50°C) → Ni(CO)4 (230°C) → Ni + 4CO

The Ni(CO)4 is a volatile complex which is easily flushed from the reaction vessel as a gas leaving the impurities behind. Industrially, the Mond process uses the same chemistry. Nickel oxides are reacted with "water gas", a mixture of CO + H2). Reduction of the oxide with the hydrogen results in impure nickel. This reacts with the CO component of the water gas to make Ni(CO)4 as above. Thermal decomposition leaves pure nickel metal.

Nickel (English) Nickel (French) Nickel (Deutsch) Nichel (Italian) Niquel (Spanish) Nickel (Swedish)

Interesting Facts:

Nickel is ferromagnetic at room temperature, just like its close periodic table neighbors iron and cobalt.

Nickel is 100 times more concentrated below Earth’s crust than in it. Nickel is believed to be the second most abundant element in the earth’s core, with iron most abundant by a large margin.

Nickel is the main metal in Mu-metal, which has the fascinating property of magnetic shielding. Magnets will normally attract metals such as iron. If you place Mu-metal between magnet and metal, the attraction disappears. This is because very little magnetic field is transmitted through Mu-metal. Mu-metal is approximately 80% nickel, 20% iron with a little molybdenum. (5)

The strange properties of nickel’s alloys don’t end with Mu-metal. Nitinol is a nickel alloy, discovered in the 1960s, that remembers its previous shape. Heat this 1:1 nickel-titanium alloy to about 500 oC, and bend it into whatever shape you like; you could bend a wire to make your name. Then cool it and bend the wire into a spring. Heat the wire again and, remarkably, the spring disappears, and the first shape – in this case your name – returns.

Nickel is corrosion resistant – it is one of the elements used in stainless steel. The presence of nickel in meteorite metal means it would have stayed bright and shiny in the hands of ancient people for much longer than if nickel had been absent.

Until the invention of rare-earth magnets, such as neodymium-iron-boron, the strongest permanent magnets – Alnico magnets – were made from a nickel alloy: mainly aluminum, nickel, cobalt and iron. Unusually, Alnico magnets retain their magnetism even when heated until they glow red hot.

Supernova 2007bi was observed in 2007. One of the products of this supernova was nickel-56, synthesized during the explosion. Nickel of mass three times greater than our entire sun was made. Nickel-56 is radioactive, decaying to cobalt-56, which itself decays to stable iron-56

Cobalt (27)

Cobalt (pronounced koh-bawlt), is a brittle, hard, silver-grey transition metal with magnetic properties similar to those of iron (ferromagnetic). Cobalt is present in meteorites and at room temperature is a solid with a close packed hexagonal structure. Ore deposits are found in Zaire, Morocco and Canada. The isotope cobalt-60 (60Co) is an artificially produced isotope used as a source of γ rays (its high energy radiation is useful for sterilization in medicine and of foods). Cobalt salts color glass a beautiful deep blue color. Cobalt compounds are important catalysts in a number of industrial processes. Cobalt is required in small amounts for life and is the only metal found in vitamins (cobalt is the critical component of vitamin B12.

•Name: Cobalt
•Symbol: Co
•Atomic number: 27
•Atomic weight: 58.933195
•Standard state: solid at 298 K
•CAS Registry ID: 7440-48-4
•Group in periodic table: 9
•Period in periodic table: 4
•Block in periodic table: d-block
•Color: lustrous, metallic, greyish-pink tinge
•Classification: Metallic

Historical information

Cobalt was discovered by Georg Brandt at 1735 in Sweden. Origin of name is from the German word "kobald" meaning "goblin" or evil spirit. Minerals containing cobalt were of value to the early civilizations of Egypt and Mesopotamia for coloring glass deep blue (my favorite transition element as far as what colors they produce!).

Cobalt was announced to be an element by Georg Brandt about 1739 (or possibly 1735). He had been trying to demonstrate that the blue color of glass was because of a new element, cobalt, rather than bismuth, an element often found in the same locations as cobalt.

Physical properties

•Melting point: 1768 [or 1495 °C (2723 °F)] K
•Boiling point: 3200 [or 2927 °C (5301 °F)] K
•Density of solid: 8900 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d7.4s2
•Shell structure: 2.8.15.2
•Term symbol: 4F9/2

Isolation

It is not normally necessary to make cobalt in the laboratory as it is available readily commercially. Many ores contain cobalt but not many are of economic importance. These include the sulfides and arsenides linnaeite, Co3S4, cobaltite, CoAsS, and smaltite, CoAs2. Industrially, however, it is normally produced as a byproduct from the production of copper, nickel, and lead. Cobalt has only one naturally occurring stable isotope and is a usually obtained as a byproduct when nickel, silver, lead, copper, and iron are mined and refined. It can be found in cobaltite, glaucodot, linnaelite, and smaltite mineral ores.

Normally the ore is "roasted" to form a mixture of metals and metal oxides. Treatment with sulphuric acid leaves metallic copper as a residue and dissolves out iron, cobalt, and nickel as the sulfates. Iron is obtained by precipitation with lime (CaO) while cobalt is produced as the hydroxide by precipitation with sodium hypochlorite (NaOCl)

2Co2+(aq) + NaOCl(aq) + 4OH-(aq) + H2O → 2Co(OH)3(s) + NaCl(aq)

The trihydroxide Co(OH)3 is heated to form the oxide and then reduced with carbon (as charcoal) to form cobalt metal.

2Co(OH)3 (heat) → Co2O3 + 3H2O

2Co2O3 + 3C → Co + 3CO2

Interesting Facts:

1. Cobalt (English) Cobalt (French) Cobalt (Deutsch) Cobalto (Italian/Spanish) Kobolt (Swedish)

2. According to the World English Dictionary, Cobalt comes from the German word “Kobalt” which is derived from the Middle High German word “kobolt” meaning “goblin” because miners believed “that malicious goblins placed it in the silver ore.”

3. Alnico alloys (containing Aluminum, Cobalt, and Nickel) are used when making powerful permanent magnets.

4. Stellite alloys (containing Chromium, Cobalt, and Tungsten) are used in the production of high-speed, high-temperature cutting tools because of Cobalt's high melting point and strength under high temperatures.

5. Other alloys containing Cobalt are used in the production of gas turbines and jet engines.

6. Cobalt's only radioactive isotope, Cobalt-60 (half-life of 5.27 years), is a source of gamma rays. It can be used in some forms of cancer treatment and as a medical tracer.

7. Compounds containing Cobalt have been used as dyes and coloring agents. The common names of some of the compounds are: Ceruleum, Cobalt blue, Cobalt green, Cobalt yellow, and new blue.

8. Cobalt is a part of the vitamin B12 (also known as cobalamin) which is of nutritional importance. According to the Office of Dietary Supplements, it is a naturally occurring water-soluble vitamin which is required for “proper red blood formation, neurological function, and DNA synthesis.” Deficiency of this mineral in daily diet can lead to “megaloblastic anemia, fatigue, weakness, constipation, loss of appetite, and weight loss.”

9. Canada, Morocco, and Zaire are important sources of Cobalt. The U.S. Geological Survey reports the possibility of Cobalt-rich zones in the north central Pacific Ocean near the Hawaiian Islands and other nearby U.S. Territories.

10. Lithium ion, Nickel-Cadmium, and Nickel metal hydride batteries are made with significant amounts of Cobalt.

11. Cobalt usage in rechargeable batteries increased from 22% in 2006 to 25% in 2007 which accounts for the fastest growing use of the metal.

12. Global Cobalt consumption in 1995 was 24,000 tons and in 2008 that number increased to 60,800 tons. That is a 7.4% increase in a span of 13 years and if demand continues it is projected that this number will grow to 72,500 tonnes in 2011.

13. Although iron is an essential mineral, too much of it is extremely toxic. Free iron in the blood reacts with peroxides to form free radicals that damage DNA, protein, lipids and other cellular components, leading to illness and sometimes death. 20 milligrams of iron per kilogram of body weight is toxic, while 60 milligrams per kilogram is lethal.

14. Iron primarily forms compounds with +2 and +3 oxidation states.

Iron (26)

Iron is a relatively abundant element in the universe. It is found in the sun and many types of stars in considerable quantity. Iron nuclei are very stable. Iron is a vital constituent of plant and animal life, and is the key component of hemoglobin.

The pure metal is not often encountered in commerce, but is usually alloyed with carbon or other metals. The pure metal is very reactive chemically..., and rapidly corrodes, especially in moist air or at elevated temperatures. Any car owner knows this. Iron metal is a silvery, lustrous metal which has important magnetic properties.

•Name: Iron
•Symbol: Fe
•Atomic number: 26
•Atomic weight: 55.845
•Standard state: solid at 298 K
•CAS Registry ID: 7439-89-6
•Group in periodic table: 8

•Period in periodic table: 4
•Block in periodic table: d-block
•Color: lustrous, metallic, greyish tinge
•Classification: Metallic

Historical information

Iron was discovered by Known since ancient times at no data in not known. Origin of name: from the Anglo-Saxon word "iron" or "iren" (the origin of the symbol Fe comes from the Latin word "ferrum" meaning "iron"). Possibly the word iron is derived from earlier words meaning "holy metal" because it was used to make the swords used in the Crusades. Iron was known in prehistoric times. Genesis says that Tubal-Cain, seven generations from Adam, was "an instructor of every artificer in brass and iron." Smelted iron artifacts have been identified from around 3000 B.C. A remarkable iron pillar, dating to about A.D. 400, remains standing today in Delhi, India. This solid pillar is wrought iron and about 7.5 m high by 40 cm in diameter. Corrosion to the pillar has been minimal despite its exposure to the weather since its erection.

Sometime prior to the autumn of 1803, the Englishman John Dalton was able to explain the results of some of his studies by assuming that matter is composed of atoms and that all samples of any given compound consist of the same combination of these atoms. Dalton also noted that in series of compounds, the ratios of the masses of the second element that combine with a given weight of the first element can be reduced to small whole numbers (the law of multiple proportions). This was further evidence for atoms. Dalton's theory of atoms was published by Thomas Thomson in the 3rd edition of his System of Chemistry in 1807 and in a paper about strontium oxalates published in the Philosophical Transactions. Dalton published these ideas himself in the following year in the New System of Chemical Philosophy. The symbol used by Dalton for iron is a circle with an ‘I’ in the center.

Physical properties

•Melting point: 1811 [or 1538 °C (2800 °F)] K
•Boiling point: 3134 [or 2861 °C (5182 °F)] K
•Density of solid: 7874 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d6.4s2
•Shell structure: 2.8.14.2
•Term symbol: 5D4

Isolation

It is not normally necessary to make iron in the laboratory as it is available commercially. Small amounts of pure iron can be made through the purification of crude iron with carbon monoxide. The intermediate in this process is iron pentacarbonyl, Fe(CO)5. The carbonyl decomposes on heating to about 250°C to form pure iron powder.

Fe + CO → Fe(CO)5 (250°C) → Fe + 5CO

The Fe(CO)5 is a volatile oily complex which is easily flushed from the reaction vessel leaving the impurities behind. Other routes to small samples of pure iron include the reduction of iron oxide, Fe2O3, with hydrogen, H2.

Nearly all iron produced commercially is used in the steel industry and made using a blast furnace. Most chemistry text books cover the blast furnace process. In essence, iron oxide, Fe2O3, is reduced with carbon (as coke) although in the furnace the actual reducing agent is probably carbon monoxide, CO.

2Fe2O3 + 3C → 4Fe + 3CO2

This process is one of the most significant industrial processes in history and the origins of the modern process are traceable back to a small town called Coalbrookdale in Shropshire (England) around the year 1773.

Interesting Facts:

1. Iron (English) Fer (French) Eisen (German) Ferro (Italian/Spanish) Järn (Swedish)

2. It is the sixth most abundant element in the universe.

3. The source of iron that was used by prehistoric men were meteorites.

4. Human beings are believed to have extracted the metal through the process of smelting, as early as 1800 to 1200 B.C. This probably began in India.

5. Cast iron was first produced in China in 550 B.C. Europeans did not catch up with the process of making it till medieval times.

6. Latin name of iron is Ferrum. It is from this word that the symbol Fe has been derived.

7. Black sands along beaches and stream banks contain the minerals taconite and magnetite. Iron is present in these minerals.

8. Indians had already mastered the art of extracting and processing the metal, the proof of which is the famous Iron Pillar in Delhi. The iron used in this structure has neither corroded nor has been affected by rust for the last 1600 years.

9. Iron is an element that has been known in its pure form for at least 5,000 years. The name "iron" comes from the Anglo-Saxon word "iron" and Scandinavian "iarn" for the metal.

10. Iron is one of the most plentiful elements. It comprises about 5.6% of the earth's crust and almost the earth’s entire core.

11. The single largest use of iron is to make steel, an alloy of iron and a smaller amount of carbon. According to archaeological records from Anatolia, man has been producing steel for at least 4,000 years.

12. Iron is not always magnetic! The ‘a’ allotrope (or form) or iron is ferromagnetic, yet if it is transformed to the b allotrope, the magnetism disappears even though the crystal lattice is unchanged.

13. Animals and plants require iron. Plants use iron in chlorophyll, the pigment used in photosynthesis. Humans use iron in hemoglobin molecules in blood to allow for the transport of oxygen to tissues throughout the body.

Manganese (25)

Manganese metal is gray-white, resembling iron, but is harder and very brittle. The metal is reactive chemically, and decomposes cold water slowly. Manganese is widely distributed throughout the animal kingdom. It is an important trace element and may be essential for utilization of vitamin B. Manganese is present in quantity the floor of oceans. It is an important component of steel.

•Name: Manganese
•Symbol: Mn
•Atomic number: 25
•Atomic weight: 54.938045
•Standard state: solid at 298 K
•CAS Registry ID: 7439-96-5
•Group in periodic table: 7
•Period in periodic table: 4
•Block in periodic table: d-block
•Color: silvery metallic
•Classification: Metallic

Historical information

Manganese was discovered by Johann Gahn at 1774 in Sweden. Origin of name is from the Latin word "magnes" meaning "magnet", or "magnesia nigri" meaning "black magnesia" (MnO2). Manganese metal was isolated by Gahn in 1774. He reduced the dioxide (MnO2, as the mineral pyrolusite) with charcoal (essentially carbon) by heating and the result was a sample of the metal manganese.

Physical properties

•Melting point: 1519 [or 1246 °C (2275 °F)] K
•Boiling point: 2334 [or 2061 °C (3742 °F)] K
•Density of solid: 7470 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d5.4s2
•Shell structure: 2.8.13.2
•Term symbol: 6S5/2

Isolation

It is not normally necessary to make manganese in the laboratory as it is available commercially. Nearly all manganese produced commercially is used in the steel industry as ferromanganese. This made by the reduction of iron oxide, Fe2O3, and manganese dioxide, MnO2, in appropriate proportions with carbon (as coke) in a blast furnace. Pure manganese is available through the electrolysis of manganese sulphate, MnSO4

Interesting Facts:

1. Manganese (English) Manganèse (French) Mangan (Deutsch) Manganese (Italian) Manganeso (Spanish) Mangan (Swedish)

2. Manganese is used most commonly in steel production to help improve strength, durability, and toughness.

3. It can be used in medicine to help support the immune system, regulate your blood sugar, and maintain bone regulation and reproduction.

4. It is also used in gasoline to reduce engine knock, and is used in alkaline batteries

5. The metal has been known to impair motor skills and cause cognitive disorders, if inhaled.

6. Manganese is found in large quantities on the floor of oceans.

7. This element may be used for drying black paints or in the preparation of oxygen and chlorine.

8. In nature, manganese may be essential for processing vitamin B1.

9. The metal is often used in quantitative analysis.

10. Fact: Manganese Helps to Prevent Bone Loss and Premenstrual Symptoms

11. Manganese often works as a trace mineral to facilitate important reactions in the body.

12. Manganese is known for helping people treat osteoporosis.

13. Manganese is an Antioxidant Facilitator, protecting cells from damage that occurs from the presence of free radicals. 14

14. Manganese Plays a Role in Stabilization of Body Functions

Manganese plays a role in the carbohydrate metabolism and the control of cholesterol levels. Carbohydrate metabolism, blood sugar control and thyroid function are all managed by manganese in the diet. Manganese deficiencies can have an adverse effect on brain function and reproduction.

15. Manganese May Alleviate Symptoms Associated with Epilepsy and Rheumatoid Arthritis (yay for me if this is so!)

Chromium (24)

Chromium is steel-gray, lustrous, hard, metallic, and takes a high polish. Its compounds are toxic. It is found as chromite ore. Siberian red lead (crocoite, PrCrO4) is a chromium ore prized as a red pigment for oil paints.

Emerald is a form of beryl (a beryllium aluminum silicate) which is green because of the inclusion of a little chromium into the beryl crystal lattice in place of some of the aluminum ions. Similarly, traces of chromium incorporated into the crystal lattice of corundum (crystalline aluminum oxide, Al2O3) as a replacement for some of the Al3+ ions results in another highly colored gem stone, in this case the red ruby.

•Name: Chromium
•Symbol: Cr
•Atomic number: 24
•Atomic weight: 51.9961
•Standard state: solid at 298 K
•CAS Registry ID: 7440-47-3
•Group in periodic table: 6
•Period in periodic table: 4
•Block in periodic table: d-block
•Color: silvery metallic (surprise surprise)
•Classification: Metallic

Historical information

Chromium was discovered by Louis-Nicholas Vauquelin at 1797 in France. Origin of name is from the Greek word "chroma" meaning "color", named for the many colored compounds known for chromium. In the mid-18th century analysis of Siberian "red lead" (PbCrO4, crocoite) from Siberia showed that it contained quite a lot of lead, but also a further material. This was eventually identified as chromium oxide. Chromium oxide was discovered in 1797 by Louis-Nicholas Vauquelin, who prepared the metal itself in the following year. Starting from crocoite the procedure was to powder the mineral and to precipitate the lead out through its reaction with hydrochloric acid (HCl in water). The residue was chromium oxide, CrO3. Heating this oxide in an oven in the presence of charcoal as a reducing agent gave the metal itself.

Vauquelin also analyzed an emerald from Peru and discovered that its green color is because of the presence of the new element, chromium. In fact, the name chromium is from the Greek word "chroma" meaning "color", so named because of the many different colored compounds displayed by chromium.

A year or two after Vauquelin's discovery, a German chemist named Tassaert working in Paris found chromium in an ore now called chromite. This ore, Fe(CrO2)2, is now an important source of chromium.

Physical properties

•Melting point: 2180 [or 1907 °C (3465 °F)] K
•Boiling point: 2944 [or 2671 °C (4840 °F)] K
•Density of solid: 7140 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d5.4s1
•Shell structure: 2.8.13.1
•Term symbol: 7S3

Isolation

It is not normally necessary to make chromium in the laboratory as it is so readily available commercially. The most useful source of chromium commercially is the ore chromite, FeCr2O4. Oxidation of this ore by air in molten alkali gives sodium chromate, Na2CrO4 in which the chromium is in the +6 oxidation state. This is converted to the Cr(III) oxide Cr2O3 by extraction into water, precipitation, and reduction with carbon. The oxide is then further reduced with aluminum or silicon to form chromium metal.

Cr2O3 + 2Al → 2Cr + Al2O3

2Cr2O3 + 3Si → 4Cr + 3SiO2

Another kind of isolation is by electroplating processes. This involves the dissolution of Cr2O3 (chromium (III) oxide) in sulphuric acid to give an electrolyte used for chromium electroplating.

Interesting Facts:

1. Chromium (English) Chrome (French) Chrom (Deutsch) Cromo (Italian) Cromo (Spanish) Krom (Swedish)

2. Chromium is a hard, lustrous, steel-gray metal.

3. Stainless steel is hard and resists corrosion due to the addition of chromium.

4. Chromium is the only element which shows antiferromagnetic ordering in its solid state at and below room temperature. Chromium becomes paramagnetic above 38°C.

5. Trace amounts of trivalent chromium are needed for lipid and sugar metabolism. Hexavalent chromium and its compounds are extremely toxic. The +1, +4 and +5 oxidation states also occur, although they are less common.

6. Chromium occurs naturally as a mix of three stable isotopes. 19 radioisotopes have been characterized.

7. Chromium is used to prepare pigments (including yellow, red and green), color glass green, color rubies red and emeralds green, in some tanning processes, as a decorative and protective metal coating and as a catalyst.

8. Chromium in air is passivized by oxygen, forming a protective layer that is essentially a spinel that is a few atoms thick.

9. Chromium is the 21st most abundant element in the Earth's crust. It is present at a concentration of approximately 100 ppm.

10. Most chromium is obtained by mining the mineral chromite. Although it is rare, native chromium also exists. It may be found in kimberlite pipe, where the reducing atmosphere favors the formation of diamond in addition to elemental chromium.

Vanadium (23)

Pure vanadium is a greyish silvery metal, and is soft and ductile. It has good corrosion resistance to alkalis, sulphuric acid, hydrochloric acid, and salt waters. The metal oxidizes readily above 660°C to form V2O5. Industrially, most vanadium produced is used as an additive to improve steels.

•Name: Vanadium
•Symbol: V
•Atomic number: 23
•Atomic weight: 50.9415
•Standard state: solid at 298 K
•CAS Registry ID: 7440-62-2
•Group in periodic table: 5
•Period in periodic table: 4
•Block in periodic table: d-block
•Color: silvery grey metallic
•Classification: Metallic

Historical information

Vanadium was discovered by Andres Manuel del Rio and Nils Sefström at 1801 in Mexico and Sweden. The element was named after "Vanadis", (a by-name of Freya referring to beauty and fertility) in Norse mythology. In 1831, Nils Gabriel Sefström (a Swedish chemist) was working with some iron ores and was able to isolate a new oxide. This lead to the element being named in honor of the Northern-Germanic tribes' goddess Vanadis  because of its beautiful multicolored compounds. In the same year, Friedrich Wöhler came in to possession of del Rio's "brown lead" and confirmed del Rio's discovery of vanadium, although the name vanadium still stands rather than del Rio's suggestion of erythronium.
The discovery of vanadium happened "twice". The discovery of vanadium was claimed first by Andres Manuel del Rio (a Spanish mineralogist) at Mexico City in 1803. He prepared a number of salts from a material contained in "brown lead" (now called vanadite, from a mine near Hidalgo in Northern Mexico). He found the colors reminiscent of those shown by chromium, so he called the element panchromium ("something which can take or have any color"). He later renamed the element erythronium ("red") [similar to erythrocytes, or red blood cells!] after noting that most of these salts turned red upon heating. It seems he withdrew his claim after a Frenchman, Collett-Desotils, disputed his claim, and it was only 30 years later that it was shown that del Rio's work was, in fact, correct.

Metallic vanadium was not made until 1867 when Henry Enfield Roscoe reduced vandium chloride (VCl3) with hydrogen gas to give vanadium metal and HCl.

Physical properties

•Melting point: 2183 [or 1910 °C (3470 °F)] K
•Boiling point: 3680 [or 3407 °C (6165 °F)] K
•Density of solid: 6110 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d3.4s2
•Shell structure: 2.8.11.2
•Term symbol: 4F3/2

Isolation

Vanadium is available commercially and production of a sample in the laboratory is not normally required. Commercially, routes leading to metallic vanadium as main product are not usually required as enough is produced as byproduct in other processes.

In industry, heating of vanadium ore or residues from other processes with salt, NaCl, or sodium carbonate, Na2CO3, at about 850°C gives sodium vanadate, NaVO3. This is dissolved in water and acidified to give a red solid which in turn is melted to form a crude form of vanadium pentoxide, "V2O5". Reduction of vanadium pentoxide with calcium, Ca, gives pure vanadium. An alternative suitable for small scales is the reduction of vanadium pentachloride, VCl5, with hydrogen, H2, or magnesium, Mg. Many other methods are also in use.

Industrially, most vanadium is used as an additive to improve steels. Rather than proceed via pure vanadium metal it is often sufficient to react the crude of vanadium pentoxide, "V2O5", with crude iron. This produces ferrovanadium suitable for further work.

Interesting Facts:

Vanadium (English) Vanadium (German) Vanadium (French) Vanadio (Italian) Vanadio (Spanish) Vanadin (Swedish)

• Vanadium is a transition element.

• Vanadium lies in the middle of the periodic table, in group 5.

• The number of electrons and protons in the vanadium atom is 23 while the number of neutrons is 28.

• The crystal structure of vanadium atom is cubic.

• Vanadium has a bright lustrous white color.

• Its compounds form different colors.

•It is highly ductile but not really malleable.

•Since it is not very reactive, vanadium does not react with oxygen or acids. However, it does react with hot sulfuric and nitric acid.

•Its specific heat capacity is 0.49 J g^-1K^-1.

•One of the peculiar characteristics of this element is that at times, it acts as a metal and sometimes as a non-metal.

•Vanadium is obtained from the minerals vanadinite, carnotite, roscoelite and patronite.

•For commercially producing vanadium, it is extracted from slag (mixture of materials which get separated from iron on purifying and float on top) and fly ash (powdered material for purifying iron)

•Vanadium is used to make strong steel alloys to be used in space vehicles, aircraft carriers, etc.

•Vanadium alloys are highly rust resistant. This makes them an excellent choice for tools and heavy equipment.

•Vanadium is also used to some extent in ceramics.

•Vanadium pentoxide can be used as a catalyst in the manufacture of dyes and printing fabrics.

•Superconducting magnets can be made from vanadium gallium tape.

Titanium (22)

Titanium is a lustrous, white metal when pure. Titanium minerals are quite common. The metal has a low density, good strength, is easily fabricated, and has excellent corrosion resistance. The metal burns in air and is the only element that burns in nitrogen. It is marvelous in fireworks.

Titanium is resistant to dilute sulphuric and hydrochloric acid, most organic acids, damp chlorine gas, and chloride solutions. Titanium metal is considered to be physiologically inert.

Titanium is present in meteorites and in the sun. Some lunar rocks contain high concentrations of the dioxide, TiO2. Titanium oxide bands are prominent in the spectra of M-type stars.

•Name: Titanium
•Symbol: Ti
•Atomic number: 22
•Atomic weight: 47.867
•Standard state: solid at 298 K
•CAS Registry ID: 7440-32-6
•Group in periodic table: 4
•Period in periodic table: 4
•Block in periodic table: d-block
•Color: silvery metallic
•Classification: Metallic

Historical information

Titanium was discovered by William Gregor at 1791 in England, who was interested in minerals.  It was named after the "Titans", (the sons of the Earth goddess in Greek mythology).  He recognized the presence of a new element, now known as titanium, in menachanite, a mineral named after Menaccan in Cornwall (England). Several years later, the element was rediscovered in the ore rutile by a German chemist, Klaproth.

The pure elemental metal was not made until 1910 by Matthew A. Hunter, who heated TiCl4 (titanium tetrachloride) together with sodium in a steel bomb at 700-800°Celsius.

Physical properties

•Melting point: 1941 [or 1668 °C (3034 °F)] K
•Boiling point: 3560 [or 3287 °C (5949 °F)] K
•Density of solid: 4507 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d2.4s2
•Shell structure: 2.8.10.2
•Term symbol: 3F2

Isolation

Titanium is readily available from commercial sources so preparation in the laboratory is not normally required. In industry, reduction of ores with carbon is not a useful option as intractable carbides are produced. The Kroll method is used on large scales and involves the action of chlorine and carbon upon ilmenite (TiFeO3) or rutile (TiO2). The resultant titanium tetrachloride, TiCl4, is separated from the iron trichloride, FeCl3, by fractional distillation. Finally TiCl4 is reduced to metallic titanium by reduction with
magnesium, Mg. Air is excluded so as to prevent contamination of the product with oxygen or nitrogen.

2TiFeO3 + 7Cl2 + 6C (900°C) → 2TiCl4 + 2FeCl3 + 6CO

TiCl4 + 2Mg (1100°C) → 2MgCl2 + Ti

Excess magnesium and magnesium dichloride is removed from the product by treatment with water and hydrochloric acid to leave a titanium "sponge". This can be melted under a helium or argon atmosphere to allow casting as bars.

Interesting facts:

Titanium is used in alloys with aluminum, molybdenum, manganese, and iron. Most of these alloys are used in the aerospace industry such as airframes and engines. It is used because it is strong, lightweight, and has the ability to withstand extreme temperatures.

Titanium is as strong as steel and much lighter. It is twice as strong as aluminum and nearly as resistant to corrosion as platinum.

Titanium is also used in joint replacement parts such as hip, ball and joint sockets.

Titanium has excellent resistance to sea water so it is used for propeller shafts, rigging, and other parts of a ship exposed to salt water. Titanium anodes coated with platinum provides cathodic protection from corrosion.

Titanium paint reflects infrared radiation so it is extensively used in solar observatories where heat could cause poor viewing conditions.

Titanium dioxide has an optical dispersion higher than a diamond.

Titanium dioxide is also used in paint because it has good covering power

Scandium (21)

We have now entered into the transition elements. This is the block in the middle which holds all of the elements with 'd' shells for their electrons. These are the more interesting metals... in my opinion.

Scandium is a silvery-white metal which develops a slightly yellowish or pinkish cast upon exposure to air. It is relatively soft, and resembles yttrium and the rare-earth metals more than it ...resembles aluminum or titanium. Scandium reacts rapidly with many acids.

Scandium is apparently a much more abundant element in the sun and certain stars than on earth.

•Name: Scandium
•Symbol: Sc
•Atomic number: 21
•Atomic weight: 44.955912
•Standard state: solid at 298 K
•CAS Registry ID: 7440-20-2
•Group in periodic table: 3
•Period in periodic table: 4
•Block in periodic table: d-block
•Color: silvery white
•Classification: Metallic

Historical information

Scandium was discovered by Lars Fredrik Nilson at 1879 in Sweden. Origin of name: from the Latin word "Scandia" meaning "Scandinavia". Scandium was discovered by Lars Frederick Nilson (a Scandinavian) in 1876 in the minerals euxenite and gadolinite, which had not yet been found anywhere except in Scandinavia. He and his coworkers were actually looking for rare earth metals. By processing 10 kg of euxenite and other residues of rare-earth minerals, Nilson was able to prepare about 2 g of scandium oxide (scandia, Sc2O3) of high purity.

In 1871 Mendeleev (father of periodic table) predicted that an element should exist that would resemble boron in its properties. He therefore called it ekaboron, (symbol Eb). Per Theodor Cleve found scandium oxide at about the same time. He noted that the new element was the element ekaboron predicted by Mendeleev in 1871.

Physical properties

•Melting point: 1814 [or 1541 °C (2806 °F)] K
•Boiling point: 3103 [or 2830 °C (5126 °F)] K
•Density of solid: 2985 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].3d1.4s2
•Shell structure: 2.8.9.2
•Term symbol: 2D3/2

Isolation

Preparation of metallic samples of scandium is not normally necessary given that it is commercially available. In practice little scandium is produced. The mineral thortveitite contains 35-40% Sc2O3 is used to produce scandium metal but another important source is as a byproduct from uranium ore processing, even though these only contain 0.02% Sc2O3.

Interesting facts:

•Scandium was named after Scandinavia. Chemist Lars Nilson was attempting to isolate the element ytterbium from the minerals euxenite and gadolinite when he discovered scandium. These minerals were primarily found in the Scandinavia region.

•Scandium is the transition metal with the lowest atomic number.

•The discovery of scandium filled a spot predicted by Mendeleev's periodic table. Scandium took the place of the placeholder element eka-boron.

•Most scandium compounds have scandium with the Sc3+ ion.

•Scandium has an abundance in the Earth's crust of 22 mg/kg (or parts per million).

•Scandium has an abundance in seawater of 6 x 10-7 mg/L (or parts per million).

•Scandium is more abundant on the Moon than on Earth.

Calcium (20)

Calcium as the element is a grey silvery metal. The metal is rather hard. Calcium is an essential constituent of leaves, bones, teeth, and shells. Calcium is the fifth most abundant element in the earth's crust and makes up more than 3% of the crust. Calcium does not occur as the metal itself in nature and instead is found in various minerals including as limestone, gypsum and fluorite. Stalagmite...s and stalactites contain calcium carbonate (CaCO3). Calcium carbonate is the basis of the cement industry.

Calcium is classified chemically as one of the alkaline earth elements (that is, in Group 2 of the periodic table. The metal is rather reactive. It readily forms a white coating of calcium nitride (Ca3N2) in air. It reacts with water and the metal burns with a yellow-red flame, forming largely the nitride.

•Name: Calcium
•Symbol: Ca
•Atomic number: 20
•Atomic weight: 40.078
•Standard state: solid at 298 K
•CAS Registry ID: 7440-70-2
•Group in periodic table: 2
•Group name: Alkaline earth metal
•Period in periodic table: 4
•Block in periodic table: s-block
•Color: silvery white
•Classification: Metallic

Historical information

Calcium was discovered by Sir Humphrey Davy at 1808 in England. Origin of name: from the Latin word "calx" meaning "lime". Compounds such as lime (CaO, calcium oxide) were prepared by the Romans in the first century under the name calx (used in explosive devices). Literature dating back to about 975 AD notes that plaster of paris (calcium sulphate, CaSO4, dehydrated gypsum) is useful for setting broken bones. Other calcium compounds used in early times include limestone (CaCO3, calcium carbonate).

Calcium metal was not isolated until 1808. After learning that Berzelius and Pontin prepared calcium amalgam by electrolysing lime in mercury, Sir Humphry Davy was able to isolate the impure metal. He did this by the electrolysis of a mixture of lime and mercuric oxide (HgO). Calcium metal was not available in large scale until the beginning of the 20th century.

Sometime prior to the autumn of 1803, the Englishman John Dalton was able to explain the results of some of his studies by assuming that matter is composed of atoms and that all samples of any given compound consist of the same combination of these atoms. Dalton also noted that in series of compounds, the ratios of the masses of the second element that combine with a given weight of the first element can be reduced to small whole numbers (the law of multiple proportions). This was further evidence for atoms. Dalton's theory of atoms was published by Thomas Thomson in the 3rd edition of his System of Chemistry in 1807 and in a paper about strontium oxalates published in the Philosophical Transactions. Dalton published these ideas himself in the following year in the New System of Chemical Philosophy.

Physical properties

•Melting point: 1115 [or 842 °C (1548 °F)] K
•Boiling point: 1757 [or 1484 °C (2703 °F)] K
•Density of solid: 1550 kg m-3

Orbital properties

•Ground state electron configuration: [Ar].4s2
•Shell structure: 2.8.8.2
•Term symbol: 1S0

Isolation

Calcium metal is readily available commercially and there is no need to make it in the laboratory. Commercially it can be made by the electrolysis of molten calcium chloride, CaCl2.

Cathode: Ca2+(l) + 2e- → Ca                                                       Anode: Cl-(l) → 1/2Cl2 (g) + e-

The calcium chloride is made by the action of hydrochloric acid upon calcium carbonate. Calcium chloride is also a byproduct in the Solway process used to make sodium carbonate:

CaCO3 + 2HCl → CaCl2 + H2O + CO2

Alternatively, and on small scale, calcium can be made through the reduction of CaO with aluminium or of CaCl2 with sodium metal:

6CaO + 2Al→ 3Ca + Ca3Al2O6

CaCl2 + 2Na→ Ca + 2NaCl

Interesting Facts:

1. It’s a metal, shiny and silvery like other metals. It is not white powder as most people think. It is a silvery white, soft alkaline earth metal.

2. Then why tablets are white? The white coating on calcium metal is an element that has reacted with the oxygen in the air and formed calcium oxide

3. It is obtained from chalk, limestone, and marble

4. There are 179 different known uses for Ca in the human body.

5. More than 99% of total body calcium is stored in the bones and teeth

6. Bones are actually a composition of protein strengthened by deposits of Ca.

7. This important elements is essential for strong bones

8. When the body is injured, it starts the healing process by stopping a blood with a blood clot.

4. It is one of the more difficult elements for the body to digest.

5. Vitamin D is needed to absorb it.

6. It can be obtained from a variety of foods. Milk and dairy products are the biggest sources.

7. It is basic component of most plants and animals as well.

8. It is very important and sometimes even essential for people with osteoporosis, colon cancer and high blood pressure.

9. Calcium is the fifth most abundant element in the earth’s crust and makes up more than 3% of the crust.

10. Human breast milk provides all the calcium a child needs.

11. People need extremely regulated calcium level because our brains rely on it. If the level is too high or too low, our nervous system gets “nervous”

12. Dark green leafy vegetables are a much better source of calcium than milk. They have almost no fat calories

13. Caffeine is “washing away” calcium. So don’t forget to add milk or cream to your morning coffee!

14. In nature, Ca carbonate is often found in nature in caves in stalagmites

15. The element name “calcium” comes from the Latin word “calcis” meaning “lime”

16. Interesting chemistry facts about an element

17. How much calcium does a human body need?
               

AGE	AMOUNT OF CALCIUM (mg)
Birth – 6 months	210
6 to 12 months	270
1 to 3 years	500
4 to 8 years	800
9 to 18 years	1300
19 to 50 years	1000
50 and older	1200