Characteristics of Some Elements



Characteristics of Some Elements

|Here are the names, symbols, atomic numbers and some simple physical characteristics of the first twenty elements plus some selected others. |

|This is not an intensive treatment and is given for general interest only. |

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|Hydrogen, H, atomic #1 -  A colourless, odourless, gaseous element. It is the lightest element and the most abundant in the universe. Present|

|in the atmosphere and in all organic compounds. It comes in three isotopes, hydrogen-1, deuterium-2, and an artificial isotope tritium-3. It |

|is found in nature as a diatomic gas, H2. Hydrogen reacts with most elements almost as if it were a metal. It acts like a metal but isn't a |

|solid like a metal because of its low mass. It was discovered by Henry Cavendish in 1776. |

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|Helium, He, atomic #2 - A colourless, odourless, gaseous, nonmetallic element belonging to the noble gases group of elements. Helium has the |

|lowest boiling point of all the known substances and can be solidified only under pressure. It is used to provide an inert environment for |

|welding and semiconductor manufacture, as a refrigerant for superconductors, and as a dilutent in breathing apparatus. It is also used to |

|fill balloons, everything from party size to the Goodyear blimp. It is totally inert chemically and has no known compounds. It was discovered|

|in the solar spectrum in 1868 by Lockyer. |

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|Lithium, Li, atomic #3 - A soft, silvery metal, the first truly metallic member of Group I in the periodic table. It is a rare element and is|

|never found uncombined by itself.  It is used in batteries and in fusion research. Lithium salts are used in psychomedicine. The element |

|reacts with oxygen and water violently and is kept under paraffin oil for this reason. On heating it reacts with nitrogen and hydrogen. |

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|Beryllium, Be, atomic #4 - A grey, metallic element of Group II. Used to manufacture Be-Cu alloys which are used in nuclear reactors as |

|reflectors and moderators. Beryllium oxide is used in ceramics and in nuclear reactors. Beryllium and its compounds are toxic and can cause |

|serious lung disease such as berylliosis. It resists oxidation because it forms an oxide layer. The element was isolated independently by F. |

|Wohler and A.A. Bussey in 1828. |

|  |

|Boron, B, atomic #5 - An element of group III. Very hard (9.3 on the Mohs scale) and a poor conductor of electricity. It is never found free |

|in nature. It is used in semiconductors and in filaments for specialized aerospace applications. Boron is used in flares to give a green |

|colour. Boron-10 is used in nuclear reactors as part of the control rods and shields. It was first discovered in 1080 by Sir Humphrey Davy, |

|J.L. Gay-Lussac and L.J. Thenard. |

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|Carbon, C, atomic #6 - A nonmetallic element belonging to group IV. Comes in three main forms, diamond, graphite and carbon (charcoal). |

|Diamond is an extremely hard and highly refractive crystal. Graphite is a soft, greyish-black slippery substance. Graphite is a good |

|conductor of heat and electricity and is used in electrical contacts, high-temperature equipment and as a solid lubricant. Graphite mixed |

|with clay is the "lead" in pencils. Carbon has the unique ability to bond to itself in long chains. For this reason all life on Earth is |

|carbon-based. |

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|Nitrogen, N, atomic #7 - A colourless, odourless, gaseous element belonging to Group V. It makes up 78% of the atmosphere and is an essential|

|component in proteins and nucleic acids in living organisms. It is obtained from the air from fractional distillation of liquid air. It is |

|also used in the manufacture of ammonia. The gas is diatomic, N2, and is used to provide an inert atmosphere in welding and metallurgy.  It |

|is relatively inert but will react with hydrogen at high temperatures and pressures. It will react with oxygen when excited with electricity |

|or lightning. It was discovered in 1772 by D. Rutherford. |

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|Oxygen, O, atomic #8 - A colourless, odourless, gaseous element belonging to Group VI. It is the most abundant element in the Earth's crust |

|(49.2%) and is present in the atmosphere (20% by volume). Atmosphere oxygen is of vital importance for all organisms that carry out aerobic |

|respiration. For industrial purposes it is obtained by the fractional distillation of liquid air. It is used in metallurgical processes to |

|produce high temperature flames and in breathing apparatus. The most common form is O2 but it can be found in an allotropic form called |

|ozone, O3, in the high atmosphere and around electrical circuits. The clear crisp smell of air after a thunderstorm is actually the smell of |

|ozone created by the lightning. |

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|Fluorine, F, atomic #9 - A poisonous, pale, yellow, gaseous element belonging to group VII. It is used in the synthesis of organic fluorine |

|compounds. Chemically it is the most reactive and electronegative non-metallic element. It is a highly dangerous compound, causing severe |

|chemical burns on contact with the skin. The element was identified by Scheele in 1771 and was first isolated by Moissan in 1886.   |

|Neon, Ne, atomic #10 - A colourless, gaseous element belonging to Group VII, the noble gases. Neon is a rare gas (0.0018% of the atmosphere) |

|and is obtained by the fractional distillation of liquid air. It is used in discharge tubes and neon lamps, in which it has a characteristic |

|red glow. It forms fluoride compounds but only under intense pressure and temperatures. For all intents and purposes it is an unreactive |

|element. It was discovered in 1898 by Sir William Ramsey and M.W. Travers.   |

|Sodium, Na, atomic #11 - A soft, silvery, reactive element belonging to Group I. Sodium was known long ago as 'natrium' hence its symbol is a|

|reflection of this. Sodium occurs as the chloride in sea water and in the mineral "halite". The metal is used as a reducing agent in chemical|

|reactions and also as a coolant in some nuclear reactors. Chemically, it is highly reactive, oxidizing in air and reacting violently with |

|water. It is stored in the lab under paraffin oil for this reason. Sodium is a major element required for life by all organisms. It was first|

|discovered and isolated by Humphrey Davy in 1807.   |

|Magnesium, Mg, atomic #12 - A silvery, metallic element belonging to Group II. The element is found in a number of minerals. It also is |

|present in seawater and is an essential element of life. Magnesium is used in a number of light alloys. Chemically, it is very reactive. In |

|air it forms a protective oxide coating but when ignited it burns with an intense white flame. It also reacts with the halogens, sulphur and |

|nitrogen. Magnesium was first isolated in 1828 by Bussy.   |

|Aluminum, Al, atomic #13 - A silvery, white, lustrous, metallic element belonging to Group III. The metal itself is highly reactive but is |

|protected by a thin transparent layer of oxide. The metal is extracted from bauxite ore, Al2O3, by electrolysis. Pure aluminum is soft and |

|ductile but its strength can be increased by alloying it with copper, manganese, zinc, silicon and magnesium. Its lightness, and strength |

|when alloyed along with its corrosion resistance and electrical conductivity (62% that of copper) make it suitable for a variety of uses. |

|These include vehicle and aircraft construction, window and door frames and overhead power cables. Although it is the third most abundant |

|element in the Earth's crust (8.1% by weight) it was not isolated until 1825 by H.C. Oersted.   |

|Silicon, Si, #14 - A metalloid element belonging to Group IV. Silicon is the second most abundant element in the Earth's crust (25.7% by |

|weight) occurring in various forms of silicon oxide. Chemically silicon is less reactive than carbon. The element combines with oxygen only |

|when red hot and is dissolved by molten alkali. The major ingredient of computer technology is the silicon chip, upon which wires are |

|engraved on an ultra thin layer of silicon crystal. The element was identified by Lavoisier in 1787 and was first isolated in 1823 by |

|Berzelius. |

|  |

|Phosphorus, P, atomic #15 - A nonmetallic element belonging to Group V. There are white (yellow), red , black and violet allotropes of this |

|element. The element is highly reactive and will spontaneously ignite with oxygen from the air. It is stored under water for this reason. |

|Phosphorus is an essential element for living organisms. Phosphorus burns on the skin are known for their deep penetration, intense pain and |

|the length of time required for healing.  Phosphorus was discovered by Brandt in 1669 when he boiled buckets of putrified urine. |

|  |

|Sulphur, S, atomic #16 - A yellow, nonmetallic element belonging to group VI. The element occurs in many sulphide and sulphate minerals and |

|native sulphur is also found in Italy and the USA. Sulphur has a variety of allotropic forms, the S8 ring being the most common. At higher |

|temperatures the rings break and form long strands numbering in the millions of S atoms long. It can be used as a plant fungicide and as an |

|ingredient in the vulcanization of rubber. The element is also used to produce sulphuric acid. |

|  |

|Chlorine, Cl, atomic #17 - A halogen element of Group VII. It is a poisonous greenish-yellow gas and occurs widely in nature as sodium |

|chloride in seawater and as the mineral halite, NaCl. It also occurs as "carnallite" which is a mixture of potassium chloride and magnesium |

|chloride and as "sylvite" which is pure potassium chloride. It has many applications including the chlorination of drinking water and the |

|manufacture of a large number of organic compounds. It reacts very well with many other elements and is a strong oxidizing agent. It was |

|discovered in 1774 by Karl Scheele and Humphry Davy confirmed it as an element in 1810. |

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|Argon, Ar, atomic #18 - A single atom element of the Noble Gas group. It is present in the air (0.93%). Argon is separated from air by |

|fractional distillation. It is slightly soluble in water, colourless, and odourless. It's uses include inert gas atmospheres for welding and |

|special-metal manufacturing such as Titanium and Zirconium. When it is mixed with nitrogen in an 80% Ar-20% N2 ratio it is used to fill |

|electric incandescent light bulbs. The element is inert chemically and has no true compounds. Lord Rayleigh and Sir William Ramsey identified|

|argon in 1894. |

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|Potassium, K, atomic #19 - Known to the ancients as "kalium" its symbol reflects this older name. Potassium is a very soft silvery metallic |

|element belonging to Group I. The element occurs in seawater and in a number of minerals. The metal has a few uses but potassium salts are |

|used in a wide range of applications. Potassium is an essential element for living organisms. Chemically it is highly reactive, resembling |

|sodium in its behaviour and compounds. It also forms an orange coloured superoxide, KO2. Potassium was discovered by Sir Humphrey Davy in |

|1807. |

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|Calcium, Ca, atomic #20 - A soft, grey, metallic element belonging to Group II. Calcium compounds are common in the Earth's crust. Limestone,|

|gypsum and marble are essentially calcium compounds. It is used as a reducing agent in the extraction of thorium, zirconium and uranium. |

|Calcium is an essential element for living organisms, being needed for the normal growth and development of bones and muscle. |

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|Iron, Fe, atomic #26 - An element that ushered in the Iron Age. It was known as "ferrum" hence its elemental symbol. A silvery, malleable and|

|ductile metallic transition element. The main sources are the ores, haematite (Fe2O3), magnetite (Fe3O4) and pyrite (FeS2).  The metal ore is|

|smelted in a blast furnace to give impure pig iron, which is further processed to give cast iron, wrought iron, and various types of steel. |

|It is the fourth most abundant element is the Earth's crust. It is required as a trace element by living organisms. Iron is quite reactive, |

|being oxidized by moist air it displaces hydrogen from acids and combines easily with nometallic elements. |

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|Nickel, Ni, atomic #28 - A malleable, ductile, silvery, metallic, transition element. Nickel is found in many ores and may make up to 20% of |

|a meteorite's mass. Nickel metal is used in special steels and is an effective catalyst. It is remarkably stable in air and is therefore an |

|ideal coinage metal. Nickel was discovered by A.F. Cronstedt in 1751. |

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|Copper, Cu, atomic #29 - Copper has been known since ancient times as "cuprum". This name has been known for about 3000 years and has been |

|linked with the island of Cryprus. The metal is malleable and ductile and it is an excellent conductor of electricity and heat. Native copper|

|appears in isolated pockets in some parts of the world. Copper metal is used to make electric cables and wires. Its alloys, brass |

|(copper-zinc) and phosphor bronze (copper-tin) are used extensively. Water does not attack copper but in moist atmospheres it slowly forms a |

|characteristic green surface layer called a patina of copper oxide. The metal will not react with dilute sulphuric or hydrochloric acid, but |

|it will react with nitric acid. Copper solutions are noted for their blue appearance. |

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|Zinc, Zn, atomic #30 - A blue-white, metallic, transition element. The metal is used in galvanizing and in a number of alloys. Chemically it |

|is a reactive metal, combining with oxygen and other nonmetals and reacting with dilute hydrochloric acid to form hydrogen gas. |

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|Bromine, Br, atomic #35 - A halogen element of group VII. It is a red volatile liquid at room temperature and has a reddish-brown vapour. |

|Chemically it is intermediate in reactivity between chlorine and iodine. The liquid is harmful to human tissue and the vapour irritates the |

|eyes and throat. The element was discovered in 1826 by Antoine Ballard and is produced commercially by extraction from seawater. |

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|Silver, Ag, atomic #47 - A white, lustrous, soft, metallic transition element. It occurs as the element in a native state and in combined |

|form as the minerals "argentite" (Ag2S) and "horn silver" (AgCl). It is also present in the ores of lead and copper and is extracted as a |

|by-product. The element is used in jewellery, tableware, and silver compounds are used in photography. Chemically, silver is less reactive |

|than copper. A dark silver sulphide forms when silver tarnishes in air because of the presence of sulphur compounds. It was known in Roman |

|times as 'argentum' hence it symbol. |

|  |

|Tin, Sn, atomic #50 - A silvery, malleable, metallic element belonging to Group IV. It is found in ores only, never in the native state. The |

|metal is used as a thin protective coating for steel plate and is a constituent of a number of alloys such as phosphor bronze, gun metal, |

|solder, Babbit metal, and pewter. Chemically it is quite reactive. It was known in the past as "stannum" hence its symbol. |

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|Antimony, Sb, atomic #51 - An element belonging to Group V. The stable form of antimony is a bluish-white metal. Yellow and black |

|non-metallic allotropic forms are also formed. The main source is stibnite (Sb2S3). The main use of the metal is as an alloying agent in |

|lead-accumulator plates, type metals, bearing alloys, solders, Britannia metal, and pewter. Its compounds are used in flame-proofing, paints,|

|ceramics, enamels, glass, dyestuffs, and rubber technology. The element will burn in air. It was first reported by Tholden in 1450 as |

|"stibium". |

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|Iodine, I, atomic #53 - A dark violet, non-metallic element belonging to Group VII. The element is insoluble in water but soluble in ethanol |

|and other organic solvents. When heated it gives a violet vapour that sublimes. Iodine is a required trace element by living organisms. It is|

|concentrated in the thyroid glands as a constituent of the thyroid hormones. The element is present in sea water and was once extracted from |

|seaweed. It is used in medicine as a mild antiseptic (dissolved in ethanol as tincture of iodine), and in the manufacture of iodine |

|compounds. Chemically, it is less reactive than the other halogens. It was discovered in 1812 by Courtois. |

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|Gold, Au, atomic #79 - A soft yellow malleable metallic transition element. It is found as the free metal in gravel or in quartz veins, and |

|is also present in some lead and copper sulphide ores. It also occurs combined with silver in "telluride sylvanite" (Au,Ag)Te2. It is used in|

|jewellery, dentistry, and electronic devices. Chemically, it is unreactive, being unaffected by oxygen. It reacts with chlorine at 200oC to |

|form gold (III) chloride. It was formally named by the Romans as "aurum" hence its symbol. |

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|Mercury, Hg, atomic #80 - A heavy, silvery, liquid metallic element belonging to the Zinc group. It is the only metal which is a fluid at |

|room temperature. It was known in ancient times as "hydroargentum" which means liquid silver. The main ore is a sulphide called "cinnabar" |

|(HgS), which can be decomposed to its elements very easily with heat.  Mercury is used in thermometers, barometers, thermostats, and other |

|scientific apparatus, and in dental amalgams as fillings. |

|  |

|Lead, Pb, atomic #82 - A heavy, dull, grey, soft, ductile, metallic element belongs to Group IV.  The main ore is the sulphide "galena" (PbS)|

|along with "litharge" (PbO). Lead has a variety of uses including building construction, lead plate accumulators, bullets and shot, and is a |

|constituent of such alloys as solder, pewter, bearing metals, type metals, and fusible alloys. Lead was used to make pipes for the Roman |

|aquaducts. The lead, known as "plumbum" was worked on by artisans who knew how to melt, mold and seal lead sheets into pipes. The artisans |

|were known as "plumbers". |

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|Uranium, U, atomic #92 - A white, radioactive, metallic element belonging to the actinoids. It occurs as uranite ore (U2O3), from which the |

|metal is extracted. Only 0.71% of the mined uranium is suitable for fission in a nuclear reactor. As a fuel and as a weapon uranium has |

|achieved enormous technical and political importance once it was first used for these purposes. It was discovered by M.H. Klaproth in 1789. |

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