Flint Magnesium
Humphry Davy's contribution and importance of lime
Calcium is an alkaline earth metal. The alkaline earth metals include beryllium, magnesium, strontium, barium and radium. The alkaline earth metals are chemically more active than most metals. Only the alkali metals in Group I (IA) are more reactive. Calcium compounds are common and abundant in the crust. Humans have used calcium compounds for hundreds of years in construction, sculpture, and roads. Calcium metal has not been prepared in a pure form until 1808 when the English chemist Humphry Davy (1778-1829) adopted an electrical current in molten calcium chloride (fused). Calcium metal has relatively few uses. However, the calcium compounds are well known and widely used. They include chalk, gypsum, limestone, marble and plaster of Paris.
It is impossible to say when the first men knew or used calcium compounds. When they used limestone to build a structure, they were using a calcium compound. Limestone is the common name for calcium carbonate (CaCO3). Every time that man has built a statue or a monument in marble, they used calcium carbonate in another form. The ancient Egyptians and Greeks used at the beginning of the mortar, a cement-like material that holds together the stones and bricks. At the beginning of mortar has been made by roasting or heating limestone for long periods of time. Water was then mixed with the powder, which would then dry to form a strong bond.
Humphry Davy (1788-1829) was a major contributor in the field of electrochemistry. He is best known for the discovery of calcium, sodium, potassium, magnesium, strontium and barium. He also discovered nitrous oxide and two types of lamps. Davy grew up in Cornwall, England, in a poor family. Its father, who died when Davy was a boy, had lost money in investments that sound to Davy helped his mother pay the debts. He did not be a student, but he loved reading about science. In later life, he said he was glad he did not study too hard because he had more time to think about his.
With no money for training, 17 years, Davy has started to work a dental surgeon, pharmacist. He also started to learn by himself on other matters of public concern, such as geography, languages and philosophy. He even wrote poems that later earned the respect and friendship of William Wordsworth, Samuel Coleridge, and other great English poets of his time! At 19, Davy read a chemistry book by the famous French scientist Antoine-Laurent Lavoisier (1743-94). This book convinced him to concentrate on chemistry. For the rest of his life, Davy's career was marked by brilliant scientific explorations of the chemistry and electrochemistry.
Davy discovered nitrous oxide, after testing the effects of hydrogen and carbon dioxide on him. (He liked to use himself as a pig Guinea the man!) From Nitrous oxide is a gas composed of nitrogen and oxygen. Although the study of nitrous oxide gas, it discovered that its effects often feel very happy or very sad. The feeling of happiness has finally given nitrous oxide by another name: laughing gas. Largest Again, Davy acknowledged that it might be used as an anesthetic, a chemical used to dull pain during minor surgery. In 1808, Davy invented the carbon arc lamp. He had proposed to use carbon as electrode material instead of metal. With electrodes carbon, it has jumped sharply electric current from one electrode to another. This has created an intense white light. Davy scored invention the beginning of the era of electric light. Arc lamps are still used today.
With his knowledge of electricity, Davy built a large battery that served to break most scientists believed elements pure substances. In 1807, he discovered the element potassium. He created this by using electrolysis. In one week, he isolated sodium similarly. Then in 1808 he used a method slightly modified to isolate calcium, magnesium, barium and strontium. Davy was only 29 when he discovered all of these elements. Davy later invented the miner lamp (now known as the Davy lamp). He learned that methane is the gas that caused mine explosions. But he realized it does ignite at high temperatures. So he designed a lamp in which the flame was surrounded by wire mesh. This reduces the heat and prevents ignition of flammable gases, which is the safest coal reducing the number of explosions in mines. Davy has been awarded numerous honors and medals for his discoveries and inventions. He died of a stroke in 1829 at the age of 49 years.
A significant calcium compound used by early civilizations was plaster of Paris. Plaster of Paris is made by heating gypsum, or calcium sulfate (CaSO4) to remove water that can crystallize. Water was added and it has hardened in a fragile, substance like cement. Until recently, it was most often used to protect the prints broken bones. However, it has been largely replaced by fiberglass, which is lighter, yet stronger. The first mention of plaster of Paris to protect Broken bones can be found in a book written by Persian Abu Mansur Muwaffaw pharmacist in about 975 AD
In 1700, chemists have learned many things on the calcium compounds. They knew that the limestone, gypsum, marble, and many other common compounds all contain a common element. They called lime element. This word comes from the Latin term lime. In 1807, Davy isolated the new element. Davy has invented a system to melt the compounds of elements which were difficult to separate by conventional methods. He passed an electric current in the compound, causing the compounds to break into two parts. One of these pieces was lime. He created the name of calcium by adding the suffix-ium in lime-ium is used to end almost all elements metal. Davy was also able to produce without sodium, potassium, strontium, magnesium and barium.
Calcium is a metal rather smooth with a shiny silver surface when the first cut. The surface quickly becomes dull that calcium reacts with oxygen to form an oxide coating Calcium white or gray. melting point of calcium is 850 ° C (1560 ° F) and the boiling point is 1440 ° C (2,620 ° F). He has a density of 1.54 grams per cubic centimeter. The calcium is moderately active. It reacts easily with oxygen to form calcium oxide (CaO). The calcium reacts with the halogen-fluorine, chlorine, bromine, iodine and astatine. Calcium also reacts easily with cold water, most acids, and most non-metals, such as sulfur and phosphorus.
Calcium is the fifth most abundant element in the crust. Its abundance is estimated approximately 3.64 per cent. It is also the fifth most abundant element in the human body. Calcium does not occur as a free element in nature. It is much too active and still exists as a compound. The calcium compound is the most common calcium carbonate (CaCO3). It is in the form of aragonite, calcite, chalk, limestone, marble, and travertine, and oyster shells and coral. Molluscs build their shells of calcium dissolved in water. When animals die or are eaten, the shells sink. For many centuries, the thick layers of shells can accumulate and be covered with mud, sand or other materials. The shells are clamped by the pressure of other materials and the water above. As they are crowded, the layer is converted to limestone. If lime is even more crowded, it can turn into marble or travertine. The calcium carbonate can be found in corals.
Six natural isotopes of calcium: calcium 40, calcium-42, calcium-43, calcium-44, calcium-46 and calcium-48exist. Radioactive isotopes calcium have also been made. Two radioactive isotopes of calcium are used in research and medicine. Calcium-45 is used to study how calcium behaves in many natural processes. For example, it can be used to see how different types of soils behave with different types of fertilizer. Calcium-45 is used as a tracer in such studies. A tracer is a radioactive isotope whose presence in a system can easily be detected. The isotope is injected into the system at some point. Within the system, the isotope emits radiation. This radiation can be monitored by sensors placed around the system. Calcium-45 can also be used as a tracer in the study of glassy materials, detergents, and systems of water purification.
Calcium and calcium-45-47 can be used to study how calcium is used in the body. The doctor may think that the body of a person is not properly use calcium from bones to or control of nerve messages. The doctor can use calcium or calcium-45-47 to learn more about this problem. The radioactive isotope is injected into the bloodstream person. Then, its trajectory can be followed by the radiation it emits. The doctor can then tell if calcium is used normally in the body. The pure metal can be made of calcium by the same method used by Davy. An electric current is passed through the molten calcium chloride. There is not much demand for pure calcium. Most Calcium is used in the form of limestone, gypsum, or other minerals that can be extracted directly from the earth. Molluscs build their shells of calcium dissolved in water.
Calcium metal has relatively few uses. It is sometimes used as a getter. " A getter is a substance that removes chemical reactions of a system. Calcium is used as a getter in the manufacture of glass ampoules under vacuum. Calcium is added to the bulb while it is underway. It then combines with gases in the glass in the final stages of manufacture. Calcium is also used as getter in the production of certain metals such as copper and steel. Calcium removes unwanted elements that would otherwise contaminate the metal. Calcium is also used to make alloys. An alloy of calcium and cerium is used in flint lighters found in (the elements that create sparks).
The starting point for making the most of the compounds of calcium is limestone. Limestone occurs naturally in large quantities in many parts of the world. It is usually extracted from quarries. A career is a big hole in the ground from which the minerals measures shall be taken. The limestone is first heated to obtain the lime or calcium oxide (CaO). Lime is one of the most important chemicals in the world. It usually ranks among the top five chemicals produced in the United States. In 1996, approximately 19 billion kilograms (42 billion pounds or 21 million tons) of lime was product in the United States.
Lime is used in the production of metals. It is used in the manufacture of steel to remove unwanted sand, or silicon dioxide (SiO2), present in iron ore. The product formed in this reaction, calcium silicate (CaSiO3) is called slag. Another use Lime is important in fight against pollution. Many plants emit harmful gases into the atmosphere through stacks. Lining a chimney with Lime allows some of these gases to be captured. Lime is known as a scrubber. Lime capture a dangerous gas, sulfur dioxide (SO2), which is a contributor to acid rain (a form of precipitation that is significantly more acidic than neutral water, often produced as a result of industrial processes). calcium sulfite (CaSO3) is a solid that can be removed from inside the chimney.
At one time, lime was used as a source of light in the rooms. When lime is heated to high temperature, it emits an intense white light. Hot Pots lime have been commonly used to line the front of the stage. The light emanated pots helped the public see the performers. Therefore, the performers were said to be "in the spotlight." This phrase is still in use today, but the lime is increasingly used as a source of light in the rooms. 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). Lime lime traps impurities in the water because it is. It carries the impurities with it as it sinks to the bottom of the tank.
Lime is used to make over 150 different industrial chemicals. Milk is a good source of calcium. Calcium is essential to both plant and animal life. In humans, it represents about two percent of the weight body. About 99 percent of calcium in the body of a person is found in bones and teeth. Milk is a good source of calcium. The body uses calcium a compound called hydroxyapatite (Ca10 (PO4) 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 deficit (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.
About the Author
Dr. Badruddin Khan teaches Chemistry in the University of Kashmir, Srinagar, India. He loves to strive hard for the cause of society, particularly, the building blocks of the soiety, the students.