Group 13-16: Post Transitional Metals, Metalloids and Nonmetal
Updated: Oct 3, 2020
Post Transition Metals:
They are also called as poor metals or other metals.
Aluminum(Al):
It is a silvery and ductile member of the poor metal group of elements, aluminum is found primarily as the ore bauxite. Although aluminum is the most abundant metal in the earth's crust, it is never found free in nature. All of the earth's aluminum has combined with other elements to form compounds. Two of the most common compounds are alum, such as potassium aluminum sulfate (KAl(SO4)2·12H2O), and aluminum oxide (Al2O3).
Physical properties:
Aluminum has low density. hence a soft and lightweight metal.
It is ductility (which allows it to be stretched into a wire), and malleability (which means it can be easily formed into a thin sheet).
Chemical properties:
It has a dull silvery appearance, because of a thin layer of oxidation that forms quickly when it is exposed to air.
Aluminum is nontoxic (as the metal).
It is nonmagnetic and non-sparking.
It is an excellent conductor of electricity and heat.
Occurrence:
Aluminum is one of the most widely used metals and also one of the most frequently found compounds in the earth's crust. It is generally found on Earth in minerals and compounds such as feldspar, beryl, cryolite, and turquoise. The ore bauxite contains large amounts of aluminum oxide. Modern processes allow for aluminum to be obtained from bauxite fairly cheaply which makes the metal to be used in a number of applications.
Uses:
Aluminum is combined with other elements such as copper, zinc, silicon, and magnesium to form alloy. These are used in the manufacture of soda cans, automobile parts, bicycles, aluminum foil, power lines, siding for houses, and even baseball bats.
Aluminum compounds includes aluminum sulfate It is used for water treatment.
Aluminum oxide is used as a reagent in various industrial processes.
Aluminum chloride is used in refining petroleum.
Discovery:
Chemist Hans Christian Orsted first produced a metal he thought was aluminum in 1825 and suggested that it was a new element. Credit is also given to Friedrich Wohler for first isolating the element in 1827. Aluminum gets its name by sir Humphry Davy, from the mineral alum, which gets its name from the Latin word "alumen" meaning "bitter salt."
Fascinating facts:
Aluminum has only one naturally occurring isotope, aluminium-27, which is not radioactive. Hence it is found in compounds only not as a free element.
Aluminum is 100% recyclable and maintains the same physical properties after recycling as the original aluminum.
When it is exposed to the air, a thin layer of aluminum oxide is formed on the surface of the metal. This prevents further corrosion and rusting.
Gallium(Ga):
Pure gallium has a stunning silvery color. Gallium is solid at normal room temperatures, but it becomes liquid when heated slightly. Gallium atoms have 31 electrons and 31 protons with 3 valence electrons in the outer shell.
Physical properties:
It is stunning silver metal.
Solid gallium is soft enough to be cut with a knife.
Chemical properties:
It is stable in air and water; but it reacts with and dissolves in acids and alkalis.
It has low melting point and high boiling point.
It has one of the widest liquid ranges of any element.
Occurrence:
Gallium does not exist in pure form in nature, and gallium compounds are not a primary source of extraction. it tends to be widely dispersed. Several ores, such as the aluminum ore bauxite, contain small amount of gallium, and coal may have a relatively high gallium content. Most gallium is produced as a byproduct of mining other metals including aluminum (bauxite) and zinc (sphalerite).
Uses:
It forms a bright, highly reflective surface when coated on glass. It can be used to create brilliant mirrors.
Gallium easily alloys with most metals, so it is used to form low-melting alloys.
Analog integrated circuits are the most common application for gallium, with optoelectronic devices (mostly laser diodes and light-emitting diodes) as the second largest end use.
Gallium has semiconductor properties, especially as gallium arsendite (GaAs). This can convert electricity to light and is used in light emitting diodes (LEDs) for electronic display and watches.
Gallium is used in some high temperature thermometers.
Discovery:
Gallium was first predicted by Russian chemist Dmitri Mendeleev. However, it was French chemist Paul Emile Lecoq de Boisbaudran who first isolated the element in 1875 and is given credit for its discovery.Gallium gets its name from the Latin word "Gallia" for "France" in honor of its discoverer's home country.
Fascinating facts :
Gallium based solar panels are used to provide power for space applications like satellites
It is used to make bright blue LEDs.
Large amounts of gallium are used at the Neutrino Observatory in Italy where it is used to study solar neutrinos produced inside the Sun.
Indium(In):
Indium is a soft, ductile, malleable, lustrous metallic metal. Its color is silvery white and it has a face-centered tetragonal structure. It is liquid over a wide range of temperatures, like gallium that belongs to its same group. Both indium and gallium are able to wet glass.
Physical properties:
Indium is a soft, ductile, malleable, lustrous metallic metal.
Its color is silvery white .
Chemical properties:
Indium is stable in air and in water but dissolves in acids.
When heated above its melting point it ignites burning with a violet flame.
Occurrence:
Indium is not widely dispersed in the environment. Cultivated soils are reported to be richer in indium than non cultivate. Indium produced in industry comes as the by-product of smelting zinc and lead sulfide ores, some of which can contain 1% indium. World production comes mainly from Canada and is around 75 tonnes per year, reserves of the metal are estimated to exceed 1500 tonnes.
Uses:
Indium is used in low-melting fusible alloys.
it is used as a protective plate for bearings and other metal surfaces.
It can be used to form corrosion-resistant mirror surface.
Indium foils are used to assess what is going on inside nuclear reactors.
It is used as light filter in low pressure sodium vapor lamps.
Discovery:
Indium was discovered by the German chemists Ferdinand Reich and Hieronymus Theodor Richter in 1863. while looking for traces of the element thallium in samples of zinc ores they found a brilliant indigo line of indium in the sample's spectrum.
Fascinating facts:
Indium can be scratched with a fingernail and bent into any shape.
It is used to coat the bearings of high speed motors since it allows for the even distribution of lubricating oil.
Tin(Sn):
Tin is not easily oxidized and resists corrosion because it is protected by an oxide film. Tin resists corrosion from distilled sea and soft tap water, This allows it to be used as a plating material to protect other metals and can be attacked by strong acids, alkalis and acid salts.
Physical properties:
Tin is a soft silvery-gray metal.
It is very malleable (meaning can be converted into a thin sheet).
It can be polished to a shine.
Chemical properties:
Tin resists corrosion from distilled sea and soft tap water.
It can be attacked by strong acids, alkalis and acid salts.
Occurence:
Tin is generally not found in its free form. It is found in the Earth's crust primarily in the ore cassiterite. It is around the 50th most abundant element in the Earth's crust. The majority of tin is mined in China, Malaysia, Peru, and Indonesia.
Uses:
Tin-plated steel containers are widely used for food preservation.
Tin alloys are employed in many ways: as solder for joining pipes or electric circuits, pewter, bell metal, babbit metal and dental amalgams.
The niobium-tin alloy is used for superconductiong magnets.
Tin oxide is used for ceramics and in gas sensors (as it absorbs a gas its electrical conmductivity increases and this can be monitored).
Tin foil was once a common wrapping material for foods and drugs, now replaced by the use of aluminium foil.
Discovery:
Tin gets its name from the Anglo-Saxon language. The symbol "Sn" comes from the Latin word for tin, "stannum." It has been known about since ancient times. Tin was first heavily used starting with the Bronze Age when tin was combined with copper to make the alloy bronze. Bronze was harder than pure copper and was easier to work with and cast.
Fascinating facts:
Tin can form two different allotropes under normal pressure. These are white tin and gray tin. White tin is the metallic form of tin we are most familiar with. Gray tin is non-metallic and is a gray powdery material. There are few uses for gray tin. White tin will transform into gray tin when the temperature falls below 13.2 degrees C. This is prevented by adding small impurities to white tin.
Bronze typically consists of 88% copper and 12% tin.
Thallium(Tl):
Thallium is very soft and malleable. It can be cut with a knife. If left in air, a heavy oxide builds up on thallium and the hydroxide is formed in the presence of water .
Physical properties:
Thallium is very soft silver grey lustrous metal.
The metal is very soft and malleable. It can be cut with a knife.
Chemical properties:
If left in air, a heavy oxide builds up on thallium.
It forms the hydroxide in the presence of water.
Thallium salts are used as reagents in chemical research.
Occurrence:
Thallium element and its compounds are toxic and should be handled carefully.
Thallium occurs in the environment naturally in small amounts. Thallium is found as a mineral in the elements crooksite, lorandite and hutchinsonite. It's also found as a trace element in iron pyrite and obtained from this ore by roasting the mineral. Small amounts of thallium are found in manganese nodules on the ocean floor.
Uses:
Thallium is used for making low-melting point special glass for highly reflective lenses.
Thallium salts are used as reagents in chemical research.
Thallium sulfate is still sold in developing countries where it is still permitted as a pesticide, although banned in Western countries.
Since its electrical conductivity changes with exposure to infrared light, it is used in photocells.
It is used for sink-float separation of minerals.
Thallium amalgam is used in thermometers for low temperature, because it freezes at -58 °C (pure mercury freezes at -38 °C).
Discovery:
British chemist William Crookes discovered thallium spectroscopically in 1861. Both Crookes and French chemist Claude Auguste Lamy isolated the element in 1862 independently. Thallium was named after the Greek word thallos, meaning green shoot or twig. It was named after its green spectral line.
Fascinating facts:
Thallium is the most toxic element on the periodic table in it's natural form.
Thallium was used as rat and ant poison in the United States until 1975, when it was banned because it started poisoning children and babies as well.
Lead(Pb):
Lead is a very heavy element.Under standard conditions lead is a soft slate grey metal with a bluish tint. It becomes a darker gray after coming into contact with air. It is very malleable (can form a thin sheet) and ductile (can be stretched into a long wire). Lead is a poor electrical conductor when compared to other metals.
Physical properties:
Lead is a slate grey lustrous metal.
It is very soft, highly malleable, ductile.
It is poor conductor of electricity.
Chemical properties:
It is very resistant to corrosion but tarnishes upon exposure to air.
It combines with other elements to make a variety of minerals including galena (lead sulfide), anglesite (lead sulfate), and cerussite (lead carbonate).
Occurrence:
Lead is not very abundant, its relative rates being smaller than those of other metals as the aluminum. It is sometimes found free in nature, but is usually obtained from the ores galena (PbS), anglesite (PbSO4), cerussite (PbCO3) and minum (Pb3O4).
Uses:
Lead is a major constituent of the lead-acid battery used extensively in car batteries.
It is used as a coloring element in ceramic glazes, as projectiles, in some candles to threat the wick.
It is the traditional base metal for organ pipes.
It is used as electrodes in the process of electrolysis.
It is used in the glass of computer and television screens, where it shields the viewer from radiation.
It is used in sheeting, cables, solders, lead crystal glassware, ammunition's, bearings and as weight in sport equipment.
Discovery:
Even though there is not a high concentration of lead in the Earth's crust, it is fairly easy to mine and refine it. It can be found in the Earth's crust in its free form, but it is mostly found in ores with other metals such as zinc, silver, and copper.
Fascinating facts:
Lead isotopes are the end products of each of the three series of naturally occurring radioactive elements.
Around 98% of all lead-acid batteries are recycled.
Bismuth(Bi):
Bismuth is the most diamagnetic of all metals, and the thermal conductivity is lower than any metal except mercury. It has a high electrical resistance and found the greatest increase in electrical resistance when placed in a magnetic field.
Physical properties:
Bismuth is a grey, crystalline, brittle metal.
Chemical properties:
Bismuth is stable to oxygen and water but dissolves in concentrated nitric air.
All bismuth salts form insoluble compounds when put into water.
Occurrence:
The most important ores of bismuth are bismuthimite and bismite. Bismuth occurs naturally as the metal itself and is found as crystals in the sulphides ores of nickel, cobalt, silver and tin. Bismuth is mainly produced as a by-product from lead and copper smelting, especially in USA.
Uses:
Bismuth metal is used in the manufacture of low melting solders and fusible alloys.
Certain bismuth compounds are also manufactured and used as pharmaceuticals.
Industry makes use of bismuth compounds as catalysts in manufacturing acrylonitrile, the starting material for synthetic fibers and rubbers.
Bismuth is sometimes used in the production of low toxicity bird shot and fishing sinkers.
Discovery:
It has been known about since ancient times. Bismuth was first shown to be a distinct element in 1753 by Claude Geoffroy the Younger.
Fascinating facts:
It is the most naturally diamagnetic of all the elements.
Its toxicity is lower than most elements.
It is twice as abundant as gold in the earth's crust.
Metalloids : These are also called semi-metals ( they have properties of metals as well as Nonmetals).
Boron(B):
Boron is the first element in the thirteenth column of the periodic table. Boron is electron-deficient, possessing a vacant p-orbital. It has several forms, the most common of which is amorphous boron, a dark brown powder. At standard temperatures boron is a poor electrical conductor but is a good conductor at high temperatures.
Physical properties:
Crystalline boron is black in color and is extremely hard.
Amorphous boron comes in the form of a dark brown powder.
Chemical properties:
It is nonreactive to oxygen, water, acids and alkalies.
It reacts with metals to form borides.
Occurrence:
Boron is a rare element on Earth. Pure boron is not found naturally on Earth, but the element is found in many compounds. The most common compounds are borax or boric acid and kernite which are found in sedimentary rock formations.
Borates are mined in US, Tibet, Chile and Turkey.
Uses:
The most economically important compound of boron is sodium tetraborate decahydrate Na2B4O7 · 10H2O, or borax, used for insulating fiberglass.
Boric acid is used in a number of applications including insecticides, flame retardants, antiseptics, and to create other compounds.
Compounds of boron are used in organic synthesis, in the manufacture of a particular type of glasses, and as wood preservatives.
Boron filaments are used for advanced aerospace structures, due to their high-strength and light weight.
It is also used in semiconductors (computer chips), magnets, super hard materials and shielding for nuclear reactors.
Discovery:
It was discovered by Sir Humphry Davy and J.L Gay-Lussac in 1808.
The name boron comes from the mineral borax which gets its name from the Arabic word "burah".
Fascinating facts:
Boron atoms can bond in a number of different types of crystal networks called allotropes.
The chemical compound boron nitride is the second hardest substance after diamond
Boron tends to form covalent bonds rather than ionic bonds.
Silicon(Si):
Silicon is the most abundant element in The Earth’s crust. It is a metalloid. It is usually tetravalent in its compounds, although sometimes its bivalent, and it is purely electropositive in its chemical behaviour. Moreover, pentacoordinated and hexacoordinated silicon compounds are also known. It is considered a semiconductor, meaning that it has electronic conductivity between that of an insulator and a conductor. Its conductivity increases with temperature. This property makes silicon a valuable element in electronics.
Physical properties:
It is a gray solid with metallic luster.
It is very brittle.
Amorphous silicon is a brown powder.
Chemical properties:
silicon can form covalent or ionic bonds either donating or sharing its four shell electrons.
It does not react with oxygen or water in its solid form.
Occurrence:
Silicon is generally not found on Earth in its free form, but is usually found in silicate minerals. These minerals account for 90% of the Earth's crust. One common compound is silicon dioxide (SiO2), which is more commonly known as silica. Silica takes on different forms including sand, flint, and quartz.
Uses:
Silicon is the principal component of glass, cement, ceramics, most semiconductor devices, and silicones, a plastic substance often confused with silicon.
Silicon is also an important constituent of some steels and a major ingredient in bricks.
It is a refractory material used in making enamels and pottery.
Elemental raw silicon and its intermetallic compounds are used as alloy integrals to provide more resistance to the aluminium, magnesium, copper and other metals.
Discovery:
It was discovered by a Swedish chemist Jons Jakob Berzelius who first isolated the element silicon and produced a sample in 1824. The name comes from the Latin word "silicus" meaning "flint." Flint is a mineral that contains silicon.
Fascinating facts:
Pure silicon is used in the manufacture of semiconductor chips for electronics. These chips form the brains of today's electronics including computers, televisions, video game consoles, and mobile phones.
Silicon Carbide (SiC) is often used as an abrasive and is nearly as hard as diamond.
Silicon has the relatively unique property for an element in that it expands when it freezes like water.It has a high melting point of 1,400 degrees Celsius and boils at 2,800 degrees Celsius.
Germanium(Ge):
Germanium is stable in air and water, and is unaffected by alkalis and acids, except nitric acid. It has 32 electrons and 32 protons with 4 valence electrons in the outer shell. It is similar in properties to the other metalloids near it in the periodic table ie silicon and arsenic.
Physical properties:
Pure germanium is a hard, lustrous, gray-white, brittle metalloid.
It has a diamond like crystalline structure
Chemical properties:
It can form covalent or ionic bonds either donating or sharing its four shell electrons.
It does not react with oxygen or water in its solid form.
Occurrence:
Germanium is a fairly rare element that is found in the Earth's crust. Although there are some minerals that contain a fair amount of germanium like germanite and argyrodite, they are too rare to be mined. The majority of germanium that is used by industry is produced as a byproduct of mining sphalerite zinc ore where it is found in small traces.
Uses:
Germanium is an important semiconductor, mainly used in transistors and integrated circuits.
Germanium oxide is added to glass to increase the index of refraction this glass is used in wide-angle lenses and in infrared devices.
Numerous alloys of germanium are prepared.
Discovery:
It was discovered by German chemist Clemens Winkler who first isolated the element and proved its existence in 1886. Winkler found the element in the mineral argyrodite. Germanium gets its name from Winkler's home country Germany.
Fascinating facts:
Germanium hydride and germanium tetrahydride are extremely flammable and even explosive when mixed with air.
It is used as a catalyst to produce some types of plastics.
Some compounds that include germanium are useful in killing bacteria while not harming animals.
Comming soon.........
Arsenic:
Antimony:
Tellurium:
Polonium:
Non-metals:
Non-Metal are those elements which do not exhibit the metallic characteristics. In the periodic table non-metals are kept almost in the right most. Some nonmetals are gases, one is liquid and some are solids. They are as Follows-
Nonmetal Gases- Hydrogen, Nitrogen, Oxygen, Fluorine and Chlorine
Nonmetal Liquid - Bromine occurs in the state of liquid
Nonmetal Solids- Carbon, Phosphorous, Sulphur, Selenium, Iodine,Astatine and Tennessine.
[Note: All Halogens are Nonmetals for Details go to Blog Group- 17: Halogens]
Hydrogen(H):
Hydrogen is the first element in the periodic table. It is the simplest possible atom composed of one proton in the nucleus and one electron in the orbit around nucleus. Hydrogen is the lightest of the elements and is the most abundant element in the universe.
Physical properties:
It is a colorless, odorless and tasteless gas.
It is very light gas.
Chemical properties:
Hydrogen is very flammable and burns when it comes into contact with oxygen.
Occurrence:
The most common place to find hydrogen on earth is in water. Each water molecule (H2 O) contains two hydrogen atoms. Hydrogen is also found in a wide range of compounds throughout the earth including hydrocarbons, acids, and hydroxides. Free hydrogen is very less because it is very light and escapes into space.
Uses:
It is used to make ammonia for fertilizers.
It is used in refining metals and methanol.
It is also used for making artificial material like plastics.
It is also used as a rocket fuel where liquid hydrogen is combined with liquid oxygen to produce a powerful explosion.
Discovery:
In 1766, Henry Cavendish was the first to discover hydrogen gas. He ran an experiment using zinc and hydrochloric acid and discovered hydrogen. Also it is found that when hydrogen burns it produce water and hence French chemist Antoine Lavoisier named hydrogen which comes from the Greek words "hydro" (meaning water) and "genes" (meaning creator).
Fascinating facts:
Hydrogen is found mostly in stars and gas planets. The Sun is made up of mainly with hydrogen.
Hydrogen becomes a liquid at very low temperature and high pressure.
It can be produced in a lab by combining a dilute acid with a metal.
Carbon(C):
Carbon has a minimum of about 1 million organic components and this number increases rapidly every year. The biggest group of all these components is the one formed by carbon and hydrogen. Carbon is unique in its chemical properties because it forms a number of components superior than all the other elements in combination with each other.
Physical properties:
Carbon is found on Earth in the form of three different allotropes
(Allotropes are materials made from the same element but in them arrangement of atoms is different ) including amorphous, graphite and diamond.
Amorphous carbon is generally black. eg coal and soot.
Diamond allotrope of carbon is transparent in color, hard and has the highest thermal conductivity of any element.
Graphite allotrope of carbon is soft material, black-gray in color and good electrical conductor.
Chemical properties:
Elemental carbon is an inert substance, insoluble in water, diluted acids and bases, as well as organic solvents.
At high temperatures it binds with oxygen to form carbon monoxide or dioxide.
It reacts with hot oxidizing agents, like nitric acid and potassium nitrate.
Among the halogens only fluorine reacts with elemental carbon.
A high number of metals combine with the element at high temperatures to form carbides.
Occurrence:
Carbon is found throughout the earth. It is a major element in many rock formations such as limestone and marble. It is found in its allotropic forms of diamond, graphite, and amorphous carbon throughout the world. Carbon is also found in many compounds including carbon dioxide in the Earth's atmosphere and dissolved in the oceans and other major bodies of water. Hydrocarbons that form many fuels such as coal, natural gas, and petroleum also contain carbon. Carbon is found in all forms of life.
Uses:
It is used for fuel in the form of coal, methane gas, and crude oil.
It is used to make all sorts of materials including plastics and alloys such as steel (a combination of carbon and iron).
It is used to make black ink for printers and painting.
Graphite is often used in making batteries, brakes, and lubricants.
It is also used to make the writing (black) part of pencils.
Diamonds are used to make fine jewelry and are considered the most valuable of all the gemstones.
Diamonds are also used for their hardness in cutting tools and precision instruments.
Discovery:
People have known about carbon as a substance since ancient times. French scientist Antoine Lavoisier determined that diamond was made of carbon in 1772. Carbon gets its name from the Latin word "carbo" meaning charcoal or coal.
Fascinating facts:
All types of life is based on carbon.
It easily forms compounds through the covalent bonding of its four valence electrons.
Plants obtain carbon from the atmosphere through the process of photosynthesis.
Carbon chains form the basis of complex molecules like DNA.
Nitrogen(N):
Nitrogen plays an important role in the life of plants and animals on Earth through the nitrogen cycle. The nitrogen cycle describes how nitrogen moves between plants, animals, bacteria, the atmosphere (the air), and soil in the ground. Nitrogen is an important element to all life on Earth.
Physical properties:
Nitrogen is colorless, odorless and tasteless element
It is diatomic non-metal gas.
Chemical properties:
Nitrogen has five electrons in its outer shell, so it is trivalent in most compounds.
Nitrogen molecules occur mainly in air. In water and soils nitrogen can be found in nitrates and nitrites.
Occurrence:
Nitrogen constitutes 78 percent of Earth's atmosphere and is a constituent of all living tissues. Nitrogen is an essential element for life, because it is a constituent of DNA and, as such, is part of the genetic code. There is very little in the Earth's crust. It can be found in some fairly rare minerals such as saltpeter.
Uses:
Nitrogen is as a component in the manufacture of ammonia.
It is used as fertilizer and to produce nitric acid.
Liquid nitrogen (LN2) is used as a refrigerant for freezing and transporting food products, for the preservation of bodies and reproductive cells (sperm and eggs), and for stable storage of biological samples.
Nitric acid salts include some important compounds, for example potassium nitrate, nitric acid, and ammonium nitrate.
Nitrated organic compounds, such as nitro-glycerine and trinitrotoluene, are often explosives.
Discovery:
Nitrogen was first discovered by Scottish chemist Daniel Rutherford in 1772. He called the gas "noxious air". Nitrogen was named by French chemist Jean-Antoine Chaptal in 1790. He named it after the mineral niter when he found that niter contained the Nitrogen gas. Niter is also called saltpeter or potassium nitrate.
Fascinating facts:
Nitrogen is very essential component of all life like carbon
Liquid nitrogen is very cold and will immediately freeze skin on contact causing severe damage.
Nitrogen plays an important role in DNA molecules.
Oxygen(O):
Oxygen is an important element that is needed by most life forms on Earth to survive because it’s the essential element in the respiratory processes of most of the living cells and in combustion processes. It is the third most abundant element in the universe and the most abundant element in the human body.
Physical properties:
oxygen is a colourless, odourless and tasteless gas.
It condensates in a light blue liquid.
Chemical properties:
Oxygen is reactive and will form oxides with all other elements except helium, neon, argon and krypton.
It is moderately soluble in water at 20 degree Celsius.
Occurrence:
It’s the most abundant element in The Earth’s crust. Nearly 21% of the air is consists of oxygen. Non-combined gaseous oxygen normally exists in form of diatomic molecules, O2, but it also exists in triatomic form, O3, named ozone. Oxygen can be separated from air by fractionated liquefaction and distillation.
Uses:
Oxygen is used in refining and manufacture of steel and other metals.
It is used in the manufacture of chemicals by controlled oxidation.
It is used in rocket propulsion.
It is used in medical and biological life support eg oxygen cylinders.
It is used in mining, production and manufacture of stone and glass products.
Discovery:
It is discovered by Joseph Priestly in 1774. He had produced oxygen gas by heating mercuric oxide and various nitrates. The name oxygen comes from the Greek word "oxygenes" meaning "acid producer". It was called this because early chemists thought that oxygen was necessary for all acids.
Fascinating facts:
Oxygen atoms make up an essential part of proteins and DNA in our bodies.
In the solar system, only the Earth has a high percentage of oxygen.
The oxygen that is found in the air is produced by photosynthesis.
The process of oxygen combining with other atoms to make compounds is called oxidation.
Phosphorus:
Phosphorous is a multivalent nonmetal. It is found in nature in several allotropic forms, and is an essential element for the life of organisms.
Physical properties:
There are several forms of phosphorous, called white, red and black phosphorous.
Chemical properties:
White phosphorous glows in the dark and it is spontaneously flammable when exposed to air and is deadly poison.
Red phosphorous can vary in colour from orange to purple, due to slight variations in its chemical structure.
Black phosphorous, is made under high pressure. it looks like graphite and, like graphite, has the ability to conduct electricity.
Occurrence:
Phosphorus is not found in its pure elemental form on Earth, but it is found in many minerals called phosphates. Most commercial phosphorus is produced by mining and heating calcium phosphate. Phosphorus is the eleventh most abundant element in the Earth's crust. Phosphorus is also found in the human body. It is the sixth most abundant element in the human body.
Uses:
Concentrated phosphoric acids are used in fertilizers for agriculture and farm production.
Phosphates are used for special glasses, sodium lamps.
It is used in steel production, in military applications (incendiary bombs, smoke screenings etc.).
It is used in many applications as: pyrotechnics, pesticides, toothpaste, detergents.
Discovery:
Phosphorus was discovered by German alchemist Hennig Brandt in 1669. He discovered phosphorus while conducting experiments with urine. Phosphorus gets its name from the Greek word "phosphoros" meaning "bringer of light." Henning Brandt picked this name because the element glowed in the dark.
Fascinating facts:
Black phosphorus looks like graphite powder and conducts electricity even though it is not a metal.
It used to be a major ingredient in detergents, but the phosphates caused algae to grow in rivers and lakes, killing many fish.
Touching white phosphorus can cause severe burns.
Sulfur:
Sulfur is a multivalent non-metal, abundant, in nature.The crystallography of sulfur is complex. Depending on the specific conditions, sulfur allotropes form several distinct crystal structures.
Physical properties:
Sulfur is tasteless and odorless.
It is a yellow crystalline solid.
Chemical properties:
In nature it occurs as the pure element or as sulfide and sulfate minerals.
Although sulfur is infamous for its smell, frequently compare to rotten eggs, that odor is actually characteristic of hydrogen sulphide (H2S).
Occurrence:
Elemental sulfur can be found in a number of areas on Earth including volcanic emissions, hot springs, salt domes, and hydrothermal vents. Sulfur is also found in a number of naturally occurring compounds called sulfides and sulfates. Some examples are lead sulfide, pyrite, cinnabar, zinc sulfide, gypsum, and barite. Sulfur can be mined from underground deposits.
Uses:
The major derivative of sulfur is sulphuric acid (H2SO4), one of the most important elements used as an industrial raw material.
Sulfur is also used in batteries, detergents, fungicides, manufacture of fertilizers, gun power, matches and fireworks.
It is used in making corrosion-resistant concrete which has great strength and is forst resistant.
It is used for solvents and in a host of other products of the chemical and pharmaceutical industries.
Discovery:
Ancient cultures in India, China, and Greece all knew about sulfur. Sometimes it is spelled "sulphur." French chemist Antoine Lavoisier in 1777, proved that sulfur was one of the elements and not a compound.
Fascinating facts:
Sulfur cycle takes place on Earth similar to other element cycles like the carbon, oxygen, and nitrogen cycles.
One of the moons of Jupiter, Io, appears yellow due to the large amount of sulfur on its surface. This sulfur comes from the many active volcanoes on the moon.
Selenium:
Selenium is a non metallic element, member of the group 16 of the period table.
Physical properties:
Selenium appears in a number of allotropic forms.
The most popular are a red amorphous powder.
A red crystalline material.
A gray crystalline metal like form called metallic selenium. This last form conducts electricity better in the light than in the dark and is used in photocells.
Chemical properties:
Selenium burns in air and is uneffected by water.
It dissolves in concentrated nitric acid and alkalis.
Occurrence:
Selenium is present in the atmosphere as metyl derivatives. There are around 40 known selenium-conaining minerals, some of which can have as much as 30% selenium - but all are rare and generally they occur together with sulfides of metals such as copper, zinc and lead. The main producing countries are Canada, USA, Bolivia and Russia.
Uses:
It is used extensively in electronics, such as photocells, light meters and solar cells.
It is used in the glass industry to remove color from glass, to give a red color to glasses and enamels.
sodium selenite is used for animal feeds and food supplements.
Selenium can also find applications in photocopying, in the toning of photographs.
Its artistic use is to intensify and extend the tonal range of black and white photographic images.
Other uses of selenium are in metal alloys such as the lead plates used in storage batteries and in rectifiers to convert AC current in DC current.
Selenium is used to improve the abrasion resistance in vulcanized rubbers.
Some selenium compounds are added to anti-dandruff shampoos.
Discovery:
Selenium was discovered by Jons Berzelius in 1817 as an impurity in sulfuric acid and named after the Greek word for earth, so he named selenium using the Greek word for moon, selene.
Fascinating facts:
Selenium is a nutritionally essential element. People need selenium for healthy joints, heart and eyes.
It plays a critical role in DNA synthesis, the immune system and the reproductive system.