Chemistry Special First Edition
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detergents, cosmetics, perfumes, textiles, paints, fuels, fertilizers, medicines, prosthetics, drinks... Our way of life would be like if we lacked chemistry.
The periodic table of the elements Classifies, organizes and distributes various chemical elements according to their properties and characteristics, its primary role is to group together elements in a specific order.
What is Chemistry? Chemistry is an experimental science which aims at the study of matter, its properties and its changing nature. All matter is made up of simple chemical elements or their compounds, each with differential characteristics. A vital process in chemistry is present: from cell to higher organisms vital activity is based on chemical reactions which transform the material and energy is exchanged. And in our daily activities we use what we offer Applied Chemistry: Plastics, computers, batteries, lighting, drinking water, soaps, 2
What is an element chemical?
How many Ătems chemicals there?
The element name is due to the Irish chemist Robert Boyle (16271691), who used to refer to a substance that can not be decomposed into simpler by ordinary chemical methods. Boyle said the number of chemical elements had to be much higher than the four that were admitting at the time and had been proposed by Empedocles (500-430 BC): water, air, fire and earth. A chemical element is a pure substance or chemically defined species whose intrinsic properties differentiate it from other elements.
As of October 2010 was officially accepted the existence of 112 items, of which only 92 are naturally occurring. The rest has been obtained from them in labs like GSI (Darmstadt, Germany), which since 1981 have discovered six new elements: Bohrium, hassio, Meitnerium, darmstadtium, roentgenium and copernicium.
How do they put the name to the elements?
If the daily existence of element by the International Union of Pure and Applied Chemistry (IUPAC), it invites its discoverers to propose a name, which must be based on a mythological concept, a mineral, a place, a property or a scientist. Along with the name, should also propose the corresponding symbol. The award of a symbol to each element was the idea of Berzelius (1779-1848), who proposed that consisted in initial Latin name of the element, followed, if there was
Thus the gold element has different properties to the element iron or oxygen element, which is not to deny that gold and iron have more in common with each other than with oxygen. In general, the chemical elements can be divided into two main groups: the metals (which are the most abundant) and nonmetals. Boyle was a forerunner of modern chemistry, as to explain the chemical transformations postulated the existence of different elementary particles. 3
repetition, by another including the name.
letter
For example, the symbol of carbon is C, the Cl Chlorine, the calcium Ca ... The symbol of an element is of universal application: it is the same in all languages, which has enabled chemists to share information. The last element is the 112 officially recognized, which has been dubbed Copernicium in homage to Copernicus, and its symbol is Cn. During period between recognizing the existence of an element to authorizing a name, names ending in "io" atomic number and constituting Latin provisional symbol a set of three letters that come from that name.
What is an atomic number? Atomic means relative to the atom, the smallest portion which can be divided into chemical element maintaining their properties. Was thought to be indivisible and hence its name. All atoms are composed of a central core in which there are positively charged particles, protons, around which moving other negatively charged particles: electrons. The atom is electrically neutral, as the load is compensated by the protons of electrons. Every atom in the number of protons in the nucleus is equal to its orbital electron, called "atomic", is characteristic of each element and the ordinal of the box engages in the Periodic Table. Except in one case (hydrogen-1) in the atomic nuclei are also neutral particles called neutrons, which provide mass but no load. Therefore, given the fact that there may be atoms of the same element, ie with the same atomic number, but with different numbers of neutrons and hence different atomic mass. As occupy the same space in Table are called4isotopes.
Knowing how and what elements make up the human body is critical to understand their behavior, physiological mechanisms and how their structures interact. An estimated 96% of our body is composed of 4 elements, in particular oxygen, carbon, hydrogen and nitrogen, primarily in the form of water.
The 12 chemicals in the human body The human body is composed of at least 60 different chemical elements, many of which are unknown purpose in the body. Of these 60, a dozen are present in larger quantities. Today we will talk about the chemistry of life, the chemical composition of our body and know the 12 chemicals in the human body in greater abundance.
Chemical composition human body
of
The remaining 4% is made up by a few other items and we could say that 99% of the body is composed of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Then expand some details.
the
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The 12 elements
formed and broken with a minimum amount of energy, it enables dynamic organic chemistry that occurs at the cellular level.
Oxygen (65%) We all know how important water is to life and 60% of body weight is water. Oxygen (O, 8) ranks first in the list and makes up 65% of the body.
Hydrogen (10%) The hydrogen (H, 1) is the most abundant chemical element in the universe. In our bodies something very similar happens along with oxygen into water ranks third on this list.
Carbon (18%) Carbon (C, 6) is one of the most important elements for life. Through the carbon, this may be
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Nitrogen (3%) Present in many organic molecules, nitrogen (N, 7) constitutes 3% of the human body. Is, for example, amino acids that make up proteins and nucleic acids of our DNA.
Calcium (1.5%) Of the minerals that make up the body, calcium (Ca, 20) is the most abundant and is vital to our development. Is practically along the whole body, in the bones and teeth for example. Moreover, they are very important in the regulation of protein.
Phosphorus (1%)
Potassium (0.25%)
Phosphorus (P, 15) is also very important to the bony structures of the body where abounds. However, also predominate in ATP molecules providing energy to cells.
Although it occupies only 0.25% of our body, potassium (K, 19) is vital to the operation. Help in regulating the heartbeat and electrical nerve signaling.
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Sulfur (0.25%)
Iron (0.006%)
Sulfur (S, 16) is equally essential in numerous organisms chemistry. It is located in the amino acids and is essential for protein shape.
Although iron (Fe, 26) ranks last in the list, it is still paramount. It is essential in the metabolism of almost all living organisms. It is found in hemoglobin, carries oxygen in red blood cells.
Sodium (0.15%) Electrolyte is another vital when it comes to electrical nerve signaling. Sodium (Na, 11) also regulates the amount of water in the body, being an equal component essential to life.
Others Other chemical elements that constitute the human body are copper, zinc, selenium, molybdenum, fluorine, iodine, manganese, cobalt, lithium, strontium, aluminum, silicon, lead, arsenic and vanadium, among others negligible proportions. In fact, little is known about the functions that many of these elements play in our body.
Chlorine (0.15%) Chlorine (CI, 17) normally found in the human body to negative ion mode, ie as chloride. This is an important electrolyte to maintain normal fluid balance in the body.
It is very interesting to know what makes up our body on a chemical level and how everything is intrinsically related to launch this very complex machine we call the human body in, do not you think? Are you surprised to know that in your body there are different amounts of these elements?
Magnesium (0.05%) Again, in the bone structure and muscles and is very important in both. Magnesium (Mg, 12), in turn, is necessary in many metabolic reactions essential for life. 8
The diamond is not the hardest natural material
authorCarlos Martin | February 18, 2009
Diamante one of the classic questions of Trivial and TV's days are numbered, and that in the classic What is the hardest material? The diamond will not be a correct answer. We've talked in the past of materials, mainly artificial or compounds harder than diamond, but this time, we are facing another natural substance, dubbed Lonsdaleite.
tests that determine these data, and also tell us that this type of material (the lonsdaleites) rarely formed when meteorites containing graphite hit Earth.
Despite this hardness and on the other hand, boron nitride has also proved to be a 18% harder than diamond performing the same tests (although in this case it is a compound), and is more versatile than diamond and Lonsdaleite, since oxygen is stable at higher temperatures diamond. And this makes it ideal to place it on the tip of cutting and drilling tools operating at high temperatures.
Also made of carbon, like diamond, has proven a 58 percent harder than the gemstone, or at least, that say in the journal New Scientist.
The team that has discovered, led by Zicheng Pan at Shanghai University, has conducted stress 9
New method for producing hydrogen clean and practical Some engineers have developed a new method to produce a clean hydrogen, which could be a key step towards ending the dependency that human civilization has on fossil fuels, and thus avoid the problems of inexorable depletion of oil and other fuels finite, and the serious environmental impact that has the widespread use of these polluting fuels.
School of Engineering at Duke University in Durham, North Carolina, USA, has been demonstrated in the laboratory by a technologically innovative new catalytic approach is feasible to reduce the levels of carbon monoxide to almost zero.
These scientists have also shown that hydrogen can be produced from processing certain types of fuel, at temperatures much lower than by conventional methods, which provides a more practical option for hydrogen production.
Hydrogen is abundant on Earth, but not pure. And extract and store molecular hydrogen to use as fuel for vehicles and in various industrial applications is expensive and complicated. Another major constraint is that a byproduct of most current methods to produce hydrogen carbon monoxide is toxic to humans and animals.
The ultimate goal of this research is to develop a convenient and clean way to generate hydrogen for use in fuel cells.
The research team Titilayo "Titi" Shodiya, working in the laboratory of Professor Nico Hotz, in the Pratt 10
Most abundant chemical elements in nature and important compound of hydrogen is water, H2O. Hydrogen is found in all living matter components and many minerals. It is also an essential part of all hydrocarbons and a variety of other organic substances. All acids contain hydrogen, one of the defining features of the acids is its dissociation in solution, producing hydrogen ions
Hydrogen It is the lightest gas that exists and has been used to inflate balloons and blimps. However, burns easily and several airships like the Hindenburg, eventually destroyed by fire. Helium, which has a 92% of the lifting capacity of the hydrogen, and it is not flammable, is used in place whenever possible. Hydrogen is typically stored in steel cylinders under pressures from 120 to 150 atmospheres. Hydrogen is also used in cutting torches, melting and soldering.
Hydrogen (Greek, "water maker), symbol M, is a reactive gaseous element, tasteless, colorless and odorless. Its atomic number is 1 and belongs to group 1 (or IA) of the periodic system.
The free state hydrogen is found only in very small amounts in the atmosphere, even in interstellar space abounds in the Sun and other stars, being in fact the most common element in the universe. In combination with other elements is widely distributed on Earth, where the most abundant 11
common isotope of helium, helium-4, probably comes from alpha emitters rocks. Natural gas, which contains an average of 0.4% helium, is the largest commercial source of helium.
Because it is incombustible, helium is a gas suitable for raising the hydrogen balloon in the air is 92% of the lifting power of hydrogen, although weighs twice as much. Helium is used to pressurize and stiffen the structure of the rocket before takeoff, and for pressurizing the liquid hydrogen tanks or other fuels, in order to force the fuel in the rocket engines. Is useful for this application because it is in a gaseous state even at the low temperature of liquid hydrogen. One potential use is as helium heat transfer medium in nuclear reactors because remains chemically inert and nonradioactive in the conditions inside the reactors.
Helium Helium (Greek helios, "sun"), symbol I, is a gaseous element, an inert, colorless and odorless. It belongs to group 18 (or VIIIa) of the newspaper, and is one of the noble gases. Its atomic number is 2.
It is the second most abundant element in the universe after hydrogen. At sea level, the helium in the atmosphere occurs at the rate of 5.4 parts per million. The ratio increases slightly to greater heights. About one part per million of atmospheric helium is helium-3, currently seen as a decay product of tritium, a radioactive isotope of hydrogen with mass 3. The 12
oxide layer in furnaces for heat treatment of steel. Among the lithium compounds are important hydroxide, used to remove carbon dioxide in the ventilation systems of spaceships and submarines, and hydride, used to inflate jackets; equivalent of heavy hydrogen (deuterium), is used to manufacture the hydrogen bomb. Lithium carbonate, a common mineral, is used in the treatment of manic-depressive psychosis
Lithium Lithium, Li symbol, is a metallic, silvery white, chemically reactive, and the lightest weight of all metals. Belongs to the group 1 (or IA) of the periodic system, and is one of the alkali metals. Its atomic number is 3.
Lithium ranked 35th in abundance among the elements in the crust. There exists in nature in the free state, but only in compounds, which are widely distributed. The metal is used as a deoxidizer and for removing unwanted gases during the production of nonferrous castings. The lithium vapor is used to prevent the carbon dioxide and oxygen to form an 13
parts are made of beryllium alloys, for its lightness, rigidity and little delay. Other applications use their resistance to magnetic fields, and their ability to not produce sparks and conduct electricity. Beryllium is widely used in so-called multiplexing systems. On a small scale, a single thread made of beryllium components of high purity can carry hundreds of electronic signals.
Beryllium
Since X-rays pass easily through pure beryllium, the element is used in the windows of X-ray tubes And beryllium oxide, the beryllia, are also used in nuclear power generation as moderators in the core of nuclear reactors, due to the tendency to retard or beryllium neutron capture.
Beryllium, symbol Be, is a metallic element, gray, brittle, with atomic number 4. Beryllium is called its principal mineral, beryl, a silicate of beryllium and aluminum.
Beryllium, one of the alkaline earth metals, ranks 51 in abundance among the natural elements of the Earth's crust. Adding beryllium to some alloys are often obtained products with high heat resistance, improved corrosion resistance, higher toughness, higher insulating properties and better casting quality. Many supersonic aircraft 14
Boron has important applications in the field of nuclear energy. Is used in particle detectors, due to its high absorption of neutrons is used as a control absorbent in nuclear reactors as a constituent material of the neutron shield.
Boron Boron, symbol B, is a semi-metallic element, brittle and hard with atomic number 5. Boron is the group 13 (III A) of the periodic low concentrations is a necessary element for plant growth, but too much is toxic. Research suggests that in addition nutritionally important for bone in humans and other vertebrates. Pure boron as normally prepared is a powder, but can be prepared by dissolving the crystalline form boron in molten aluminum and cooling it slowly. 15
temperatures. The physical properties of the three forms differ significantly due to differences in crystal structure. In diamond, the hardest material known, each atom is bonded to four others in a three dimensional structure, while graphite is loosely bound sheets of atoms arranged in hexagons.
Carbon has the unique ability to bond to other carbon atoms to form compounds and cyclic chain complex. This property leads to an almost infinite number of carbon compounds, the most common being those containing carbon and hydrogen. His first compounds were identified in the early nineteenth century in living matter, and because of that, the study of carbon compounds chemical called 'organic'
Carbon Carbon, symbol C, is crucial for the existence of living organisms, and has many important industrial applications. Its atomic number is 6, and belongs to group 14 (or IVA) of the periodic system.
Carbon is an element widely distributed in nature, but is only 0.025% of the Earth's crust, where it exists mainly in the form of carbonates. Carbon dioxide is a major component of the atmosphere and the main carbon
The three forms of elemental carbon existing in nature (Diamond, graphite and amorphous carbon) are solids with extremely high melting points, and insoluble in all solvents at ordinary 16
source is incorporated into living matter. Through photosynthesis, plants convert carbon dioxide into organic carbon compounds, which are then consumed by other organisms
method (see dating), to estimate the age of fossils and other organic matter. This isotope is continuously produced in the atmosphere by cosmic rays, and is incorporated into all living matter. As 14C decays with a period of half-life of 5760 years, the ratio of carbon 14 to carbon 12 in a specimen given, provides a measure of approximate age.
The isotope carbon-13 and carbon14 are used as tracers (see Isotopic Tracer) in biochemical research. Carbon-14 is also used in a technique called carbon-14
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Nitrogen makes four-fifths (78.03%) of the volume of air. Is inert and acts as a diluting agent of oxygen in the combustion process and respiration. It is an important element in plant nutrition. Certain soil bacteria fix nitrogen and transform Most of the nitrogen used in the chemical industry are obtained by fractional distillation of liquid air and used to synthesise ammonia. From this ammonia prepare a variety of chemicals, such as fertilizers, nitric acid, urea, hydrazine and amines. Ammonia is also used to produce nitrous oxide (N2O), a colorless gas commonly known as laughing gas. This gas, mixed with oxygen, is used as a surgical anesthetic.
Nitrogen Nitrogen gas is a toxic, colorless, odorless and tasteless. Can be condensed in the form of a colorless liquid which, in turn, can be compressed as a colorless crystalline solid. Nitrogen occurs in two isotopic forms natural artificially radioactive isotopes have won four. It is extracted from air by passing air through hot copper or iron, the oxygen is separated from air leaving the nitrogen mixed with inert gases. Pure nitrogen is obtained by fractional distillation of liquid air. Liquid nitrogen having a boiling point lower than the liquid oxygen, nitrogen distilled before allowing to separate.
Liquid nitrogen has widespread application in the field of cryogenics as cooling agent. Their use has increased with the advent of ceramic materials that become superconductive at the boiling point of nitrogen (see Superconductivity).
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combined, Breath.
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alive.
See
There are three known structural forms of oxygen: ordinary oxygen, which contains two atoms per molecule and whose formula is O2, ozone, which contains three atoms per molecule and whose formula is O3, and a non-magnetic pale blue, the O4 contains four atoms per molecule and readily decomposes ordinary oxygen. There are three stable isotopes of oxygen: oxygen 16 (atomic mass 16) is the most abundant. Represents 99.76% of ordinary oxygen and was used in the determination of atomic masses to the 1960s
Oxygen Oxygen, symbol O, is slightly magnetic gaseous element, colorless, odorless and tasteless. Oxygen is the most abundant element on Earth Oxygen makes up 21% by volume or 23.15% by mass of the atmosphere, 85.8% by mass of the oceans (pure water contains 88.8% oxygen), 46.7% in mass of the crust (as a component of most rocks and minerals). Oxygen accounts for 60% of the human body. It is found in all living tissues. Almost all plants and animals, including humans, need oxygen, either in the free or
Using large amounts of oxygen in the welding torches at high temperature, in which the mixture of oxygen and another gas produces a flame with a temperature much higher than that of the burning gases in air. Oxygen is administered to patients with respiratory problems and also those flying at high altitudes, where the low oxygen concentration does not allow 19
normal breathing. The oxygenenriched air is used to make steel in open-hearth furnaces. High purity oxygen is used in the metal fabrication industries. It is very important as a liquid propellant guided missiles and rockets. Fluorine (Latin fluo, 'flow') of symbol F, is a gaseous element, chemically reactive and poisonous. Group is in the 17 (or VIIa) of the periodic table, and is one of the halogens. Its atomic number is 9
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