Teeth, sea shells, bones and cave stalactites are all products of calcium. Interestingly, calcium seems to come in fifth place wherever it goes: It is the fifth most abundant element by mass in the Earth's crust after oxygen, silicon, aluminum and iron ; the fifth most abundant dissolved ion in seawater after sodium, chloride, magnesium and sulfate ; and the fifth most abundant element in the human body after oxygen, carbon, hydrogen and nitrogen.
It is, however, the most abundant metallic element in the human body, 99 percent of which can be found in our bones and teeth about 2 lbs. In its pure elemental state, calcium is a soft, silvery-white alkaline earth metal.
It is important to note, however, that calcium is never found in this isolated state in nature, but exists instead in compounds. Calcium compounds can be found in a variety of minerals, including limestone calcium carbonate , gypsum calcium sulfate and fluorite calcium fluoride , according to Chemicool.
Calcium makes up about 4. In order to isolate pure calcium, it must be extracted through electrolysis, a technique that uses a direct electrical current to separate elements from their naturally occurring sources. Once isolated, calcium is quite reactive and will form a grayish-white oxide and nitride coating when exposed to air. Calcium Ca is No. Calcium comes from the Latin word "calx," meaning lime.
This is not a reference to the fruit, but rather calcium oxide CaO , the useful building material derived from heated limestone. In , Cornish chemist and inventor Sir Humphry Davy was the first person to successfully isolate calcium. This time, Davy repeated their electrolysis method on the same calcium amalgam, but he added more lime to the mixture, producing more of the amalgam from which he was able to distill away the mercury, leaving only calcium, according to the Royal Society of Chemistry.
Once calcium had been successfully isolated, the element was able to be studied further, revealing its importance for the survival of all living things. Calcium is extremely important to the human body. Calcium, vitamin K, and a protein called fibrinogen help the platelets to form a clot. If your blood is lacking calcium or one of these other nutrients, it will take longer than normal for your blood to clot.
The ability to detect extremely small amounts of an element can be a very useful adaptation for an animal if that element is important to it.
For example, hermit crabs, which inhabit second hand shells and change to newer, bigger shells as they grow, have the ability to recognise shells suitable for occupation not only by feeling for them, but apparently also by measuring the minute amount of calcium carbonate that is dissolved in the water around a shell.
They can readily distinguish natural shells containing calcium carbonate from calcium-bearing replicas made from calcium sulphate. The concentration of calcium detected by the hermit crab is in the order of 4ppm or less, which is amazingly low. So from strong teeth and bones, through to good tasting beer and ensuring hermit crabs find their perfect home -you can see that calcium really is an essential element. Well, I'm very at home with my hard water, and the local beer tastes quite good too, although I do get through quite a few kettles - indeed Russell Hobbs probably owe their buoyant share price just down to me.
Well, maybe. Next week, if you were an element which one would you be? If I had to choose a person to represent gold, then I guess it might be an ambitious young stockbroker, a bit flashy, and not great at forming relationships.
For helium - an airy-fairy blonde with a bit of a squeaky voice, but with aspirations to join the nobility. And for boron? Well at first glance a boring, middle-aged accountant, maybe wearing brown corduroys and a tweed jacket. And you can get the inside story on Boron's swinging antics with Pat Bailey in next week's Chemistry in its Element. I'm Chris Smith, thank you for listening and goodbye.
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Temperature K. Pressure Pa. Listen to Calcium Podcast. Transcript : Chemistry in its element: calcium Promo You're listening to Chemistry in its element brought to you by Chemistry World , the magazine of the Royal Society of Chemistry. Karen Faulds Milk, cheese, yogurt, spinach, almonds. The alkaline earth metals make up Group 2 IIA of the periodic table, a chart that shows how the elements are related.
They include beryllium, magnesium, strontium, barium, and radium. The alkaline earth metals are more chemically active than most metals. Only the alkali metals in Group I IA are more reactive.
Calcium compounds are common and abundant in the Earth's crust. Humans have used calcium compounds for hundreds of years in construction, sculpture, and roads. Calcium metal was not prepared in a pure form until when English chemist Humphry Davy passed an electric current through molten melted calcium chloride.
Metallic calcium has relatively few uses. However, calcium compounds are well known and widely used. They include chalk, gypsum, limestone, marble, and plaster of paris. It is impossible to say when humans first knew about or used compounds of calcium. Whenever they used limestone to build a structure, they were using a compound of calcium.
Limestone is the common name for calcium carbonate CaCO 3. Whenever humans built a statue or monument out of marble, they were using calcium carbonate in another form. Ancient Egyptians and early Greeks used mortar, a cement-like material that holds stones and bricks together. Early mortar was 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. H umphry Davy was a major contributor to the field of electrochemistry. This is the science involving the relation of electricity to chemical changes. He is best known for discovering 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. His father, who died when Davy was a boy, had lost money in unwise investments, so Davy helped his mother pay off the debts. He disliked being a student, though he liked reading about science. In later life, he said he was happy he did not study too hard because he had more time to think on his own. With no money for further education, the year-old Davy began to work for a surgeon-pharmacist.
He also started learning on his own about other subjects that interested him, such as geography, languages, and philosophy. He even wrote poems that later earned him the respect and friendship of William Wordsworth, Samuel Coleridge, and other leading English poets of his time! That book convinced him to concentrate on chemistry. For the rest of his life, Davy's career was marked by brilliant scientific explorations in chemistry and electrochemistry.
Davy discovered nitrous oxide after testing the effects of hydrogen and carbon dioxide on himself. He liked to use himself as a human guinea pig!
Nitrous oxide is a gas consisting of nitrogen and oxygen. While studying nitrous oxide gas, he discovered that its effects often made him feel very happy or very sad. The feeling of happiness eventually gave nitrous oxide another name: laughing gas. Most importantly, though, Davy recognized that it could be used as an anesthetic. An anesthetic is a chemical used to dull pain during minor surgery. In , Davy invented the carbon arc lamp. He had proposed using carbon as the electrode material instead of metal.
Electrodes are conductors used to establish electrical contact with a nonmetallic part of a circuit. With carbon electrodes, he made a strong electric current leap from one electrode to the other. This created an intense white light. Davy's invention marked the beginning of the era of electric light. Arc lamps are still used today. Using his knowledge of electricity, Davy built a large battery which he used to break down substances most scientists thought were pure elements.
In , he discovered the element potassium. He created this by using electrolysis. Electrolysis produces chemical changes by passage of an electric current through an electrolyte. An electrolyte is a nonmetallic electric conductor. Within a week he isolated sodium in a similar way. Then in , he used a slightly modified method to isolate calcium, magnesium, barium, and strontium.
Davy was only 29 by the time he had discovered all of these elements! Davy later invented the miner's lamp now known as the Davy lamp. He learned that methane was the mine gas that caused explosions. But he realized it ignited only at high temperatures. So he designed a lamp in which the flame was surrounded by wire gauze. This reduced the heat and prevented flammable gases from igniting.
This made coal-mining safer by reducing the number of explosions in mines. Davy was rewarded by many honors and medals for his discoveries and inventions. He died of a stroke in at the age of Another calcium compound used by early civilizations was plaster of paris. Plaster of paris is made by heating gypsum, or calcium sulfate CaSO 4 , to remove the water that makes it crystallize.
Water was added and it hardened into a brittle, cement-like substance. Until recently, it was most often used to make casts to protect broken bones. However, it has largely been 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 pharmacist Abu Mansur Muwaffaw in about A.
By the s, chemists had learned a great deal about calcium compounds. They knew that limestone, gypsum, marble, and many other commonly occurring compounds all contain a common element.
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