Calcium metal has relatively few uses. It is sometimes used as a "getter. Calcium is used as a getter in the manufacture of evacuated glass bulbs. It then combines with gases left in the glass in the final stages of manufacture. Calcium is also used as a getter in the production of certain metals, such as copper and steel. The calcium removes unwanted elements that would otherwise contaminate the metal. Calcium is also used to make alloys. An alloy is made by melting and mixing two or more metals.
The mixture has properties different from those of the individual metals. An alloy of calcium and cerium is used in flints found in lighters the elements that create sparks. The starting point for the manufacture of most calcium compounds is limestone. Limestone occurs naturally in large amounts in many parts of the world. It is usually mined from open-pit quarries.
A quarry is a large hole in the ground from which useful minerals are taken. Lime is one of the most important chemicals in the world. It usually ranks in the top five chemicals produced in the United States. In , about 19 billion kilograms 42 billion pounds or 21 million tons of lime was produced in the United States. Lime is used in the production of metals. It is used during the manufacture of steel to remove unwanted sand, or silicon dioxide SiO 2 , present in iron ore:.
The product formed in this reaction, calcium silicate CaSiO 3 , is called slag. Another important use of lime is in pollution control. Many factories release harmful gases into the atmosphere through smokestacks.
Lining a smokestack with lime allows some of these gases to be captured. The lime is known as a scrubber. Lime captures one harmful gas, sulfur dioxide SO 2 , which is a contributor to acid rain a form of precipitation that is significantly more acidic than neutral water, often produced as the result of industrial processes :. Calcium sulfite CaSO 3 is a solid that can be removed from the inside of the smokestack. At one time, lime was used as a source of light in theaters. When lime is heated to a high temperature, it gives off an intense white light.
Pots of hot lime were often used to line the front of the stage. The light the pots gave off helped the audience see the performers. As a result, the performers were said to be "in the limelight. Lime is also used in water purification and waste treatment plants. When water combines with water, it forms slaked lime, or calcium hydroxide Ca OH 2 :.
Slaked lime traps impurities present in the water as it forms. It carries the impurities with it as it sinks to the bottom of the tank. Lime is used to make more than different industrial chemicals. Some examples of these chemicals with their uses are:. Calcium is essential to both plant and animal life. In humans, it makes up about two percent of body weight. About 99 percent of the calcium in a person's body is found in bones and teeth.
Milk is a good source of calcium. The body uses calcium in a compound known as hydroxyapatite Ca 10 PO 4 6 OH 2 to make bones and teeth hard and resistant to wear. Calcium has many other important functions in the human body. For example, it helps control the way the heart beats. An excess too much or deficiency not enough of calcium can change the rhythm of the heart and cause serious problems. Calcium also controls the function of other muscles and nerves. Toggle navigation.
Photo by: kk-artworks. Discovery and naming It is impossible to say when humans first knew about or used compounds of calcium. Humphry Davy English chemist.
Physical properties Calcium is a fairly soft metal with a shiny silver surface when first cut. Chemical properties Calcium is a moderately active element. It reacts readily with oxygen to form calcium oxide CaO : Calcium reacts with the halogens— fluorine, chlorine, bromine, iodine, and astatine, The halogens are the elements that make up Group 17 VIIA of the periodic table.
Occurrence in nature Calcium is the fifth most common element in the Earth's crust. Isotopes Six naturally occurring isotopes of calcium exist: calcium, calcium, calcium, calcium, calcium, and calcium Extraction Pure calcium metal can be made by the same method used by Davy. An electric current is passed through molten calcium chloride: There is not much demand for pure calcium.
Uses Calcium metal has relatively few uses. Compounds The starting point for the manufacture of most calcium compounds is limestone. Limestone is first heated to obtain lime, or calcium oxide CaO : Lime is one of the most important chemicals in the world. It is used during the manufacture of steel to remove unwanted sand, or silicon dioxide SiO 2 , present in iron ore: The product formed in this reaction, calcium silicate CaSiO 3 , is called slag.
Lime captures one harmful gas, sulfur dioxide SO 2 , which is a contributor to acid rain a form of precipitation that is significantly more acidic than neutral water, often produced as the result of industrial processes : Calcium sulfite CaSO 3 is a solid that can be removed from the inside of the smokestack. Health effects Calcium is essential to both plant and animal life. Other articles you might like:. Also read article about Calcium from Wikipedia.
User Contributions: 1. Glazed Donuts. Thank you very much! It is also used in making cements and mortar that are used in builldings.
The calcium oxide, CaO, is produced by thermal decomposition of carbonated minerals in furnaces, applying a continuous bed process. The oxide is used in high intensity light arcs lime light for its unusual spectral characteristics and as dehydrating industrial agent.
The metallurgic industry extensively uses the oxide during the reduction of ferrous alloys. The calcium oxide, Ca OH 2 , has many applications in which the hydroxyl ion is necessary. In the process of calcium hydroxide quenching, the volume of blown out lime [Ca OH 2 ] expends to double the initial quantity of quick lime CaO , fact that makes it useful to break down rocks or wood.
The quick lime is an excellent absorbent for the carbon dioxide, because it produces carbonate, which is very insoluble. The calcium silicate, CaSi, prepared in an electric oven from lime, silica and reducing carbonated agents, is useful as a steel-deoxidizing agent. The acetylene is the base material of a great number of important chemicals for the organic industrial chemistry. The pure calcium carbonate occurs in two crystalline forms: calcite, hexagonal shaped, which possesses birrefringent properties, and aragonite, rhombohedric.
The natural carbonates are the most abundant calcium minerals. The Iceland spar and the calcite are essentially pure carbonate forms, whilst the marble is impure and much more compact, reason why it can be polished. Although the calcium carbonate is very little soluble in water, it is quite soluble if the water contains dissolved carbon dioxide, for in these solutions it forms bicarbonate when dissolving. This fact explains the cave formation, where the lime stone deposits have been in contact with acid waters.
The calcium halogenures include phosphorescent fluoride, which is the calcium compound more abundant and with important applications in spectroscopy. The calcium chloride possesses, in the anhydric form, great deliquescence capacity, which makes it useful as industrial dehydrating agent and as sand whirl control factor in roads. Calcium hypochlorite whitening powder is produced in the industry when passing chlorine through a lime solution, and has been used as a whitening agent and as water purifier.
The dehydrated calcium sulphate is the mineral gypsum, constitutes the bigger portion of Portland concrete, and has been used to reduce the alkalinity of soils. Heating gypsum at high temperatures produces a calcium sulphate hemihydrate, which is sold with the commercial name of Parisian stucco. The calcium compounds account for 3.
The distribution of calcium is very wide; it is found in almost every terrestrial area in the world. Seawater contains 0. Calcium is always present in every plant, as it is essential for its growth.
Calcium is the most abundand metal in the human body: is the main constituent of bones and theets and it has keys metabolic functions.
Strontium is a shiny, relatively soft metal. The name of the element is derived from Strontian, a town in Scotland where the mineral strontianite was discovered, from which strontium was first isolated.
It is found in the Earth's crust at a concentration of ppm, making it the 16th most abundant element. Strontium salts produce brilliant red colors when heated, and are used in fireworks and flares for this reason. Radioactive strontium a beta-emitter is produced in nuclear explosions; since it is chemically similar to calcium, it becomes incorporated into bone in people who are exposed to it.
Strontium is a beta-emitter, and interferes with the production of red blood cells. Barium is a shiny, soft metal. The name of the element is derived from the Greek word barys , which means "heavy," in reference to the high density of some barium minerals.
It is found in the Earth's crust at a concentration of ppm, making it the 14th most abundant element. Barium was discovered in the s in the form of the "Bologna stones" now known to be barium sulfate, BaSO 4 discovered near Bologna, Italy. These stones glowed in the presence of light, and also when heated. Barium salts give off a green color when heated, and are used in fireworks in the form of barium nitrate, Ba NO 3 2.
Barium sulfate, BaSO 4 , is poisonous, but it is so insoluble that that it passes through the body before any absorption of barium can take place. It is used in the diagnosis of some intestinal problems in the form of "barium enemas": barium sulfate is opaque to X-rays, and can be used to take X-rays of the digestive tract. Radium is a soft, shiny, radioactive metal. The name of the element was derived from the Latin word for "ray," radius , because of its ability to glow in the dark with a faint blue light.
It is found in the Earth's crust at a concentration of 0. It is found in trace amounts in uranium ores, but commercially used radium is more easily obtained from spent nuclear fuel.
Radium was discovered by Pierre and Marie Curie in ; they extracted a milligram of radium from three tons of uranium ore. Radium is produced in the radioactive decay of uranium, uranium, thorium, and plutonium After its discovery, and before the dangers of radiation were understood, radium was used in a lot of quack cures and patent medicines. Radium was used to make glow-in-the-dark clock faces in the early 's; the alpha particles emitted by the radium struck particles of zinc sulfide, causing them to glow, but were stopped by the clock's casing by by the glass in the clock face.
Many of the workers who painted these clock faces became ill, or died of radiation sickness.
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