A chemical element is a type of atom that is distinguished by its atomic number; that is, by the number of protons in its nucleus. The periodic table of the chemical elements is a tabular method of displaying the Chemical elements Although precursors to this table exist its invention is See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton The proton ( Greek πρῶτον / proton "first" is a Subatomic particle with an Electric charge of one positive The nucleus of an Atom is the very dense region consisting of Nucleons ( Protons and Neutrons, at the center of an atom The term is also used to refer to a pure chemical substance composed of atoms with the same number of protons. A chemical substance is a Material with a definite chemical composition. 
Common examples of elements are hydrogen, carbon, nitrogen, and oxygen. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the In total, 117 Elements have been observed as of 2007, of which 94 occur naturally on Earth. Elements with atomic numbers 83 or higher (bismuth and above) are inherently unstable, and undergo radioactive decay. Bismuth (ˈbɪzməθ is a Chemical element that has the symbol Bi and Atomic number 83 Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. Of the first 82 elements, 80 have stable isotopes. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides Elements 43 and 61 (technetium and promethium) have no stable isotopes, and decay. Technetium (tɛkˈniːʃɪəm is the lightest Chemical element with no Stable isotope. Promethium (prəˈmiːθiəm/ /proʊˈmiːθiəm is a Chemical element with the symbol Pm and Atomic number 61 The elements from 83 to atomic number 94 that have no stable nuclei, are nevertheless found in nature, either surviving as remnants of the primordial stellar nucleosynthesis which produced the elements in the solar system, or else as produced newly as short-lived daughter-isotopes in the natural decay of uranium and thorium. Uranium (jʊˈreɪniəm is a silvery-gray Metallic Chemical element in the Thorium (ˈθɔːriəm is a Chemical element with the symbol Th and Atomic number 90 
All chemical matter consists of these elements. Matter is commonly defined as being anything that has mass and that takes up space. New elements of higher atomic number are discovered from time to time, as products of artificial nuclear reactions. In Nuclear physics, a nuclear reaction is the process in which two nuclei or nuclear particles collide to produce products different from the initial particles
The term 'elements' (stoicheia) was first used by the Greek philosopher Plato in about 360 BCE, in his dialogue Timaeus, which includes a discussion of the composition of inorganic and organic bodies and is a rudimentary treatise on chemistry. Dmitri Ivanovich Mendeleev (sometimes spelled Mendeleyev; Дми́трий Ива́нович Менделе́ев) ( &ndash) was a Russian chemist and The periodic table of the chemical elements is a tabular method of displaying the Chemical elements Although precursors to this table exist its invention is Biography Early life Birth and family Plato was born in Athens Greece Timaeus ( Greek: Τίμαιος, Timaios) is a theoretical treatise of Plato in the form of a Socratic dialogue, written Plato assumed that the minute particle of each element corresponded to one of the regular polyhedra: tetrahedron (fire), octahedron (air), icosahedron (water), and cube (earth). A regular polyhedron is a Polyhedron whose faces are congruent (all alike Regular polygons which are assembled in the same way around each Vertex A tetrahedron (plural tetrahedra) is a Polyhedron composed of four triangular faces three of which meet at each vertex. An octahedron (plural octahedra is a Polyhedron with eight faces In Geometry, an icosahedron ( Greek: eikosaedron, from eikosi twenty + hedron seat /ˌaɪ A cube is a three-dimensional solid object bounded by six square faces facets or sides with three meeting at each vertex. 
Adding to the four elements of the Greek philosopher Empedocles, in about 350 BC, Aristotle also used the term "element" and conceived of a fifth element called "quintessence", which formed the heavens. Many ancient philosophies used a set of archetypal classical "elements" to explain patterns in Nature. Empedocles ( Greek:, ca 490–430 BC was a Greek Pre-Socratic Philosopher and a citizen of Agrigentum, a Greek colony in Aristotle (Greek Aristotélēs) (384 BC – 322 BC was a Greek philosopher a student of Plato and teacher of Alexander the Great. According to ancient and medieval science, aether (Greek grc αἰθήρ aithēr) also spelled æther or ether, is the material that fills Aristotle defined an element as:
Element – one of those bodies into which other bodies can be decomposed and which itself is not capable of being divided into other. 
Building on this theory, in c. 790 Arabian chemist Jabir ibn-Hayyan (Geber) postulated that metals were formed out of two elements: sulphur, ‘the stone which burns’, which characterized the principle of combustibility, and mercury, which contained the idealized principle of metallic properties. For the 12th century astronomer see Jabir ibn Aflah. For the anonymous 14th century Spanish alchemist see Pseudo-Geber.  Shortly thereafter, this evolved into the Arabic concept of the three principles: sulphur giving flammability or combustion, mercury giving volatility and stability, and salt giving solidity.
In 1524, Swiss chemist Paracelsus adopted Aristotle’s four element theory, but reasoned that they appeared in bodies as Geber’s three principles. Paracelsus (11 November or 17 December 1493 in Einsiedeln Switzerland – 24 September 1541 in Salzburg, Austria) was an alchemist, Paracelsus saw these principles as fundamental, and justified them by recourse to the description of how wood burns in fire. Mercury included the cohesive principle, so that when it left in smoke the wood fell apart. Smoke represented the volatility (the mercury principle), the heat-giving flames represented flammability (sulphur), and the remnant ash represented solidity (salt). 
In 1669, German physician and chemist Johann Becher published his Physica Subterranea. Johann Joachim Becher (6 May 1635 &ndash October 1682 was a German Physician, alchemist, precursor of Chemistry, scholar and adventurer best In modification on the ideas of Paracelsus, he argued that the constituents of bodies are air, water, and three types of earth: terra fluida, the mercurial element, which contributes fluidity and volatility; terra lapida, the solidifying element, which produces fusibility or the binding quality; and terra pinguis, the fatty element, which gives material substance its oily and combustible qualities.  These three earths correspond with Geber’s three principles. A piece of wood, for example, according to Becher, is composed of ash and terra pinguis; when the wood is burnt, the terra pinguis is released, leaving the ash. In other words, in combustion the fatty earth burns away.
In 1661, Robert Boyle showed that there were more than just four classical elements as the ancients had assumed. Robert Boyle was a Natural philosopher, chemist physicist inventor and early Gentleman scientist, noted for his work in Physics and Chemistry Many ancient philosophies used a set of archetypal classical "elements" to explain patterns in Nature.  The first modern list of chemical elements was given in Antoine Lavoisier's 1789 Elements of Chemistry, which contained thirty-three elements, including light and caloric. Light, or visible light, is Electromagnetic radiation of a Wavelength that is visible to the Human eye (about 400–700 By 1818, Jöns Jakob Berzelius had determined atomic weights for forty-five of the forty-nine accepted elements. Friherre Jöns Jacob Berzelius (20 August 1779 &ndash 7 August 1848 was a Swedish chemist Dmitri Mendeleev had sixty-six elements in his periodic table of 1869. Dmitri Ivanovich Mendeleev (sometimes spelled Mendeleyev; Дми́трий Ива́нович Менделе́ев) ( &ndash) was a Russian chemist and The periodic table of the chemical elements is a tabular method of displaying the Chemical elements Although precursors to this table exist its invention is
From Boyle until the early 20th century, an element was defined as a pure substance that cannot be decomposed into any simpler substance. A chemical substance is a Material with a definite chemical composition.  Put another way, a chemical element cannot be transformed into other chemical elements by chemical processes. Chemistry (from Egyptian kēme (chem meaning "earth") is the Science concerned with the composition structure and properties In 1913, Henry Moseley discovered that the physical basis of the atomic number of the atom was its nuclear charge, which eventually led to the current definition. Henry Gwyn Jeffreys Moseley ( November 23, 1887 – August 10, 1915) was an English physicist. The current definition also avoids some ambiguities due to isotopes and allotropes. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides Allotropy (Gr allos, other and tropos, manner is a behavior exhibited by certain Chemical elements these elements can exist in two or more different
By 1919, there were seventy-two known elements.  In 1955, element 101 was discovered and named mendelevium in honor of Mendeleev, the first to arrange the elements in a periodic manner. Mendelevium (ˌmɛndəˈlɛviəm is a Synthetic element with the symbol Md (formerly Mv) and the Atomic number 101 In October 2006, the synthesis of element 118 was reported; however, element 117 has not yet been created in the laboratory.
The lightest elements are hydrogen and helium, both created by Big Bang nucleosynthesis during the first 20 minutes of the universe in a ratio of around 3:1 by mass (approximately 12:1 by number of atoms). Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical In Physical cosmology, Big Bang nucleosynthesis (or primordial nucleosynthesis) refers to the production of nuclei other than those of H-1 (i This timeline of the Big Bang describes the events according to the Scientific theory of the Big Bang, using the cosmological time parameter of Comoving coordinates A ratio is an expression which compares quantities relative to each other Almost all other elements found in nature, including some further hydrogen and helium created since then, were made by various natural or (at times) artificial methods of nucleosynthesis, including occasionally by activities such as nuclear fission. Nucleosynthesis is the process of creating new atomic nuclei from preexisting Nucleons (protons and neutrons Nuclear fission is the splitting of the nucleus of an atom into parts (lighter nuclei) often producing Free neutrons and other smaller nuclei which may
As of 2006, there are 117 known elements (in this context, "known" means observed well enough, even from just a few decay products, to have been differentiated from any other element).  Of these 117 elements, 94 occur naturally on Earth. Six of these occur in extreme trace quantities: technetium, atomic number 43; promethium, number 61; astatine, number 85; francium, number 87; neptunium, number 93; and plutonium, number 94. Technetium (tɛkˈniːʃɪəm is the lightest Chemical element with no Stable isotope. Promethium (prəˈmiːθiəm/ /proʊˈmiːθiəm is a Chemical element with the symbol Pm and Atomic number 61 Astatine (ˈæstətiːn is a Radioactive Chemical element with the symbol At and Atomic number 85 Francium (ˈfrænsiəm formerly known as eka-caesium and actinium K, is a Chemical element that has the symbol Fr and Neptunium (nɛpˈtjuːniəm is a Chemical element with the symbol Np and Atomic number 93 These 94 elements, and also possibly element 98 californium, have been detected in the universe at large, in the spectra of stars and also supernovae, where short-lived radioactive elements are newly being made. Californium (ˌkælɪˈforniəm is a Metallic Chemical element with the symbol Cf and Atomic number 98
The remaining 22 elements not found on Earth or in astronomical spectra have been derived artificially. All of the elements that are derived solely through artificial means are radioactive with very short half-lives; if any atoms of these elements were present at the formation of Earth, they are extremely likely to have already decayed, and if present in novae, have been in quantities too small to have been noted. Half-Life (computer-game page here It's already listed in the disambiguation page Technetium was the first purportedly non-naturally occurring element to be synthesized, in 1937, although trace amounts of technetium have since been found in nature, and the element may have been discovered naturally in 1925. Technetium (tɛkˈniːʃɪəm is the lightest Chemical element with no Stable isotope. This pattern of artificial production and later natural discovery has been repeated with several other radioactive naturally occurring trace elements.
Lists of the elements by name, by symbol, by atomic number, by density, by melting point, and by boiling point as well as Ionization energies of the elements are available. Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of Chemical elements, sorted by name Wikipedia talkFeatured lists for an explanation of this and other inclusion tags below -->This is a list of chemical elements by symbol, including the A table of Chemical elements ordered by Atomic number and color coded according to type of element This is a list of the Chemical elements sorted by Density measured at Standard temperature and pressure. This is a list of the Chemical elements sorted by Melting point measured at normal pressure This is a list of the Chemical elements arranged by Boiling point measured at standard atmospheric pressure, given in the Kelvin, Celsius, and These tables list the Ionization energy in kJ/mol necessary to remove one mole of Electrons from one mole of neutral gaseous Atoms (first energy respectively The most convenient presentation of the elements is in the periodic table, which groups elements with similar chemical properties together. The periodic table of the chemical elements is a tabular method of displaying the Chemical elements Although precursors to this table exist its invention is
The atomic number of an element, Z, is equal to the number of protons which defines the element. See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton For example, all carbon atoms contain 6 protons in their nucleus; so the atomic number "Z" of carbon is 6. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 The nucleus of an Atom is the very dense region consisting of Nucleons ( Protons and Neutrons, at the center of an atom Carbon atoms may have different numbers of neutrons, which are known as isotopes of the element. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides
The number of protons in the atomic nucleus also determines its electric charge, which in turn determines the electrons of the atom in its non-ionized state. Electric charge is a fundamental conserved property of some Subatomic particles which determines their Electromagnetic interaction. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J Ionization is the physical process of converting an Atom or Molecule into an Ion by adding or removing charged particles such as Electrons This in turn (by means of the Pauli exclusion principle) determines the atom's various chemical properties. The Pauli exclusion principle is a quantum mechanical principle formulated by Wolfgang Pauli in 1925 A chemical property is any of a material's properties that becomes evident during a Chemical reaction; that is any quality that can be established only by changing a substance's So all carbon atoms, for example, ultimately have identical chemical properties because they all have the same number of protons in their nucleus, and therefore have the same atomic number. It is for this reason that atomic number rather than mass number (or atomic weight) is considered the identifying characteristic of an element. The mass number ( A) also called atomic mass number or nucleon number, is the total number of Protons and Neutrons (together known as The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass
The mass number of an element, A, is the number of nucleons (protons and neutrons) in the atomic nucleus. The mass number ( A) also called atomic mass number or nucleon number, is the total number of Protons and Neutrons (together known as In Physics a nucleon is a collective name for two Baryons the Neutron and the Proton. Different isotopes of a given element are distinguished by their mass numbers, which are conventionally written as a super-index on the left hand side of the atomic symbol (e. g. , 238U).
The relative atomic mass of an element is the average of the atomic masses of all the chemical element's isotopes as found in a particular environment, weighted by isotopic abundance, relative to the atomic mass unit (u). The atomic mass (ma is the Mass of an atom most often expressed in unified atomic mass units The atomic mass may be considered to be the total mass The unified atomic mass unit ( u) or Dalton ( Da) or sometimes universal mass unit, is an unit of Mass used to express This number may be a fraction which is not close to a whole number, due to the averaging process. On the other hand, the atomic mass of a pure isotope is quite close to its mass number. Whereas the mass number is a natural (or whole) number, the atomic mass of a single isotope is a real number which is close to a natural number. In general, it differs slightly from the mass number as the mass of the protons and neutrons is not exactly 1 u, the electrons also contribute slightly to the atomic mass, and because of the nuclear binding energy. Binding energy is the Mechanical energy required to disassemble a whole into separate parts For example, the mass of 19F is 18. 9984032 u. The only exception to the atomic mass of an isotope not being a natural number is 12C, which has a mass of exactly 12, due to the definition of u (it is fixed as 1/12th of the mass of a free carbon-12 atom, exactly).
Isotopes are atoms of the same element (that is, with the same number of protons in their atomic nucleus), but having different numbers of neutrons. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides This article is a discussion of neutrons in general For the specific case of a neutron found outside the nucleus see Free neutron. Most (66 of 94) naturally occurring elements have more than one stable isotope. Thus, for example, there are three main isotopes of carbon. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 All carbon atoms have 6 protons in the nucleus, but they can have either 6, 7, or 8 neutrons. Since the mass numbers of these are 12, 13 and 14 respectively, the three isotopes of carbon are known as carbon-12, carbon-13, and carbon-14, often abbreviated to 12C, 13C, and 14C. Carbon in everyday life and in chemistry is a mixture of 12C, 13C, and 14C atoms. Chemistry (from Egyptian kēme (chem meaning "earth") is the Science concerned with the composition structure and properties
All three of the isotopes of carbon have the same chemical properties. But they have different nuclear properties. In this example, carbon-12 and carbon-13 are stable atoms, but carbon-14 is unstable; it is slightly radioactive, decaying over time into other elements. Carbon-14, 14C, or radiocarbon, is a Radioactive isotope of Carbon discovered on February 27, 1940, by Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation.
Like carbon, some isotopes of various elements are radioactive and decay into other elements upon radiating an alpha or beta particle. Isotopes (Greek isos = "equal" tópos = "site place" are any of the different types of atoms ( Nuclides Radioactive decay is the process in which an unstable Atomic nucleus loses energy by emitting ionizing particles and Radiation. For certain elements, all their isotopes are radioactive isotopes: specifically the elements without any stable isotopes are technetium (atomic number 43), promethium (atomic number 61), and all observed elements with atomic numbers greater than 82. See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton
Of the 80 elements with a stable isotope, 16 have only one stable isotope, and the mean number of stable isotopes for the 80 stable elements is 3. 4 stable isotopes per element. The largest number of stable isotopes that occur for an element is 10 (for tin, element 50).
Some elements can be found as multiple elementary substances, known as allotropes, which differ in their structure and properties. Allotropy (Gr allos, other and tropos, manner is a behavior exhibited by certain Chemical elements these elements can exist in two or more different For example, carbon can be found as diamond, which has a tetrahedral structure around each carbon atom; graphite, which has layers of carbon atoms with a hexagonal structure, and fullerenes, which have nearly spherical shapes. In Mineralogy, diamond is the allotrope of carbon where the carbon atoms are arranged in The Mineral graphite, as with Diamond and Fullerene, is one of the Allotropes of carbon. "C60" and "C-60" redirect here For other uses see C60 (disambiguation. The ability for an element to exist in one of many structural forms is known as 'allotropy'.
The standard state, or reference state, of an element is defined as its thermodynamically most stable state at 1 bar at a given temperature (typically at 298. In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly 15 K). In thermochemistry, an element is defined to have an enthalpy of formation of zero in its standard state. In Thermodynamics and Physical chemistry, thermochemistry is the study of the Heat evolved or absorbed in Chemical reactions Thermochemistry The standard enthalpy of formation or "standard heat of formation" of a compound is the change of Enthalpy that accompanies the formation of 1 mole of a For example, the reference state for carbon is graphite, because it is more stable than the other allotropes.
The naming of elements precedes the atomic theory of matter, although at the time it was not known which chemicals were elements and which compounds. When it was learned, existing names (e. g. , gold, mercury, iron) were kept in most countries, and national differences emerged over the names of elements either for convenience, linguistic niceties, or nationalism. For example, the Germans use "Wasserstoff" for "hydrogen" and "Sauerstoff" for "oxygen", while English and some romance languages use "sodium" for "natrium" and "potassium" for "kalium", and the French, Greeks, Portuguese and Poles prefer "azote/azot/azoto" for "nitrogen". English is a West Germanic language originating in England and is the First language for most people in the United Kingdom, the United States The Romance languages (sometimes referred to as Romanic languages, or Neolatin languages) are a branch of the Indo-European language family comprising all
But for international trade, the official names of the chemical elements both ancient and recent are decided by the International Union of Pure and Applied Chemistry, which has decided on a sort of international English language. A table of Chemical elements ordered by Atomic number and color coded according to type of element The International Union of Pure and Applied Chemistry ( IUPAC) (aɪjuːpæk or ay-yoo-pec) is an international Non-governmental organization That organization has recently prescribed that "aluminium" and "caesium" take the place of the US spellings "aluminum" and "cesium", while the US "sulfur" takes the place of the British "sulphur". But chemicals which are practicable to be sold in bulk within many countries, however, still have national names, and those which do not use the Latin alphabet cannot be expected to use the IUPAC name. According to IUPAC, the full name of an element is not capitalized, even if it is derived from a proper noun such as the elements californium or einsteinium (unless it would be capitalized by some other rule). Californium (ˌkælɪˈforniəm is a Metallic Chemical element with the symbol Cf and Atomic number 98 Einsteinium (aɪnˈstaɪniəm is a Metallic Synthetic element. Capitalization (or capitalisation &mdash see spelling differences) is writing a word with its first letter as a Majuscule (upper case letter Isotopes of chemical elements are also uncapitalized if written out: carbon-12 or uranium-235. Carbon-12 is the most abundant of the two stable Isotopes of the element Carbon, accounting for 98 Uranium-235 is an isotope of uranium that differs from the element's other common isotope Uranium-238, by its ability to cause a rapidly expanding fission
In the second half of the twentieth century physics laboratories became able to produce nuclei of chemical elements that have a half life too short for them to remain in any appreciable amounts. Half-Life (computer-game page here It's already listed in the disambiguation page These are also named by IUPAC, which generally adopts the name chosen by the discoverer. This can lead to the controversial question of which research group actually discovered an element, a question which delayed the naming of elements with atomic number of 104 and higher for a considerable time. (See element naming controversy). The names for the Chemical elements 104 to 109 were the subject of a major Controversy starting in the 1960s which was finally resolved in 1997
Precursors of such controversies involved the nationalistic namings of elements in the late nineteenth century. For example, lutetium was named in reference to Paris, France. Lutetium (ljuːˈtiːʃiəm is a Chemical element with the symbol Lu and Atomic number 71 The Germans were reluctant to relinquish naming rights to the French, often calling it cassiopeium. The British discoverer of niobium originally named it columbium, in reference to the New World. Niobium (naɪˈoʊbiəm or columbium (/kəˈlʌmbiəm/ is a Chemical element that has the symbol Nb and Atomic number 41 The New World is one of the names used for the non-Eurasian/non-African parts of the Earth specifically the Americas and Australia. It was used extensively as such by American publications prior to international standardization.
Before chemistry became a science, alchemists had designed arcane symbols for both metals and common compounds. Alchemy a part of the Occult Tradition is both a philosophy and a practice with an ultimately unknown aim involving the improvement of the alchemist as well as the making of These were however used as abbreviations in diagrams or procedures; there was no concept of atoms combining to form molecules. With his advances in the atomic theory of matter, John Dalton devised his own simpler symbols, based on circles, which were to be used to depict molecules. John Dalton FRS (6 September 1766 &ndash 27 July 1844 was an English Chemist, Meteorologist and Physicist.
The current system of chemical notation was invented by Berzelius. Friherre Jöns Jacob Berzelius (20 August 1779 &ndash 7 August 1848 was a Swedish chemist In this typographical system chemical symbols are not used as mere abbreviations - though each consists of letters of the Latin alphabet - they are symbols intended to be used by peoples of all languages and alphabets. The first of these symbols were intended to be fully universal; since Latin was the common language of science at that time, they were abbreviations based on the Latin names of metals - Fe comes from Ferrum, Ag from Argentum. Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. The symbols were not followed by a period (full stop) as abbreviations were. Later chemical elements were also assigned unique chemical symbols, based on the name of the element, but not necessarily in English. For example, sodium has the chemical symbol 'Na' after the Latin natrium. Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 The same applies to "W" (wolfram) for tungsten, "Hg" (hydrargyrum) for mercury, "K" (kalium) for potassium, "Au" (aurum) for gold, "Pb" (plumbum) for lead, and "Sb" (stibium) for antimony. Tungsten (ˈtʌŋstən also known as wolfram (/ˈwʊlfrəm/ is a Chemical element that has the symbol W and Atomic number 74 Mercury (ˈmɜrkjʊri also called quicksilver or hydrargyrum, is a Chemical element with the symbol Hg ( Latinized hydrargyrum Potassium (pəˈtæsiəm is a Chemical element. It has the symbol K (kalium from qalīy Atomic number 19 and Atomic mass 39 Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 Characteristics Lead has a dull luster and is a dense, Ductile, very soft highly Antimony (IPA (Received Pronunciation, /ˈæntɪmoʊni/ (US is a Chemical element with the symbol Sb (stibium meaning "mark" and
Chemical symbols are understood internationally when element names might need to be translated. There are sometimes differences; for example, the Germans have used "J" instead of "I" for iodine, so the character would not be confused with a roman numeral. Roman numerals are a Numeral system originating in ancient Rome, adapted from Etruscan numerals.
The first letter of a chemical symbol is always capitalized, as in the preceding examples, and the subsequent letters, if any, are always lower case (small letters).
There are also symbols for series of chemical elements, for comparative formulas. These are one capital letter in length, and the letters are reserved so they are not permitted to be given for the names of specific elements. For example, an "X" is used to indicate a variable group amongst a class of compounds (though usually a halogen), while "R" is used for a radical, meaning a compound structure such as a hydrocarbon chain. Abundance Owing to their high Reactivity, the halogens are found in the environment only in compounds or as Ions Halide ions and oxoanions In Chemistry, radicals (often referred to as free radicals) are atoms molecules or ions with Unpaired electrons on an otherwise Open shell The letter "Q" is reserved for "heat" in a chemical reaction. "Y" is also often used as a general chemical symbol, although it is also the symbol of yttrium. Yttrium (ˈɪtriəm is a Chemical element with symbol Y and Atomic number 39 "Z" is also frequently used as a general variable group. "L" is used to represent a general ligand in inorganic and organometallic chemistry. In Chemistry, a ligand is either an Atom, Ion, or Molecule (see also Functional group) that bonds to a central metal generally "M" is also often used in place of a general metal.
The three main isotopes of the element hydrogen are often written as H for protium, D for deuterium and T for tritium. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Deuterium, also called heavy hydrogen, is a Stable isotope of Hydrogen with a Natural abundance in the Oceans of Earth Tritium (ˈtɹɪtiəm symbol or, also known as Hydrogen-3) is a radioactive Isotope of Hydrogen. This is in order to make it easier to use them in chemical equations, as it replaces the need to write out the mass number for each atom. It is written like this:
D2O (heavy water)
Instead of writing it like this:
The periodic table of the chemical elements is a tabular method of displaying the chemical elements. Heavy water is water which contains a higher proportion than normal of the Isotope Deuterium, as deuterium oxide, D2O or ²H2O The periodic table of the chemical elements is a tabular method of displaying the Chemical elements Although precursors to this table exist its invention is Although precursors to this table exist, its invention is generally credited to Russian chemist Dmitri Mendeleev in 1869. Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending Dmitri Ivanovich Mendeleev (sometimes spelled Mendeleyev; Дми́трий Ива́нович Менделе́ев) ( &ndash) was a Russian chemist and Mendeleev intended the table to illustrate recurring ("periodic") trends in the properties of the elements. The layout of the table has been refined and extended over time, as new elements have been discovered, and new theoretical models have been developed to explain chemical behavior.
The periodic table is now ubiquitous within the academic discipline of chemistry, providing an extremely useful framework to classify, systematize and compare all the many different forms of chemical behavior. The table has also found wide application in physics, biology, engineering, and industry. The current standard table contains 117 confirmed elements as of January 27, 2008 (while element 118 has been synthesized, element 117 has not).
During the early phases of the Big Bang, nucleosynthesis of hydrogen nuclei resulted in the production of hydrogen and helium isotopes, as well as very minuscule amounts (on the order of 10-10) of lithium and beryllium. See also Abundances of the elements (data page The abundance of a Chemical element measures how relatively common the element is or how much of the element The Big Bang is the cosmological model of the Universe that is best supported by all lines of scientific evidence and Observation. In Physical cosmology, Big Bang nucleosynthesis (or primordial nucleosynthesis) refers to the production of nuclei other than those of H-1 (i There is argument about whether or not some boron was produced in the Big Bang, as it has been observed in some very young stars, but no heavier elements than boron were produced. As a result, the primordial abundance of atoms consisted of roughly 75% 1H, 25% 4He, and 0. 01% deuterium. Deuterium, also called heavy hydrogen, is a Stable isotope of Hydrogen with a Natural abundance in the Oceans of Earth  Subsequent enrichment of galactic halos occurred due to Stellar nucleosynthesis and Supernova nucleosynthesis. A spiral galaxy is a Galaxy belonging to one of the three main classes of galaxy originally described by Edwin Hubble in his 1936 work “The Realm of the Stellar nucleosynthesis is the collective term for the nuclear reactions taking place in Stars to build the nuclei of the heavier elements. Supernova nucleosynthesis is the production of new Chemical elements inside Supernovae It occurs primarily due to explosive Nucleosynthesis during explosive  However intergalactic space can still closely resemble the primordial abundance, unless it has been enriched by some means. Intergalactic space is the physical space between galaxies. Generally free of dust and debris intergalactic space is very close to a total Vacuum.
The following table shows the twelve most common elements in our galaxy (estimated spectroscopically), as measured in parts per million, by mass.  Nearby galaxies that have evolved along similar lines have a corresponding enrichment of elements heavier than hydrogen and helium. The more distant galaxies are being viewed as they appeared in the past, so their abundances of elements appear closer to the primordial mixture. As physical laws and processes appear common throughout the visible universe, however, it is expected that these galaxies will likewise have evolved similar abundances of elements. In Big Bang Cosmology, the observable universe is the region of space bounded by a Sphere, centered on the observer that is small enough that
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The first transuranium element (element with atomic number greater than 92) discovered was neptunium in 1940. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Neon (ˈniːɒn is the Chemical element that has the symbol Ne and Atomic number 10 Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14 Magnesium (mægˈniːziəm is a Chemical element with the symbol Mg, Atomic number 12 Atomic weight 24 Sulfur or sulphur (ˈsʌlfɚ see spelling below) is the Chemical element that has the Atomic number 16 Potassium (pəˈtæsiəm is a Chemical element. It has the symbol K (kalium from qalīy Atomic number 19 and Atomic mass 39 Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28 In Chemistry, transuranium elements (also known as transuranic elements) are the Chemical elements with Atomic numbers greater than 92 (the atomic See also List of elements by atomic number In Chemistry and Physics, the atomic number (also known as the proton Neptunium (nɛpˈtjuːniəm is a Chemical element with the symbol Np and Atomic number 93 As of August 2007, only the elements up to 111, Roentgenium, have been confirmed as valid by IUPAC, while more or less reliable claims have been made for synthesis of elements 112, 113, 114, 115, 116 and 118. Roentgenium (rɛntˈgɛniəm /rʌntˈdʒɛniəm/ is a Chemical element in the Periodic table that has the symbol Rg and Atomic number The International Union of Pure and Applied Chemistry ( IUPAC) (aɪjuːpæk or ay-yoo-pec) is an international Non-governmental organization Ununtrium (juːˈnʌntriəm or /əˈnʌntriəm/ is the temporary name of a Synthetic element in the Periodic table that has the temporary symbol Uut and Ununquadium (ˌjuːnənˈkwɒdiəm or /ˌʌnənˈkwɒdiəm/ is the temporary name of a radioactive Chemical element in the Periodic table that has the Ununpentium (ˌjuːnənˈpɛntiəm or /ˌʌnənˈpɛntiəm/ is the temporary name of a synthetic Superheavy element in the Periodic table that has the Ununhexium (ˌjuːnənˈhɛksiəm or /ˌʌnənˈhɛksiəm/ is the temporary name of a synthetic Superheavy element in the Periodic table that has the temporary Ununoctium (ˌjuːnəˈnɒktiəm or /ˌʌnəˈnɒktiəm/ also known as eka-radon or element 118, is the temporary IUPAC name for The heaviest element that is believed to have been synthesized to date is element 118, ununoctium, on October 9, 2006, by the Flerov Laboratory of Nuclear Reactions in Dubna, Russia. Ununoctium (ˌjuːnəˈnɒktiəm or /ˌʌnəˈnɒktiəm/ also known as eka-radon or element 118, is the temporary IUPAC name for Dubna (Дубна́ is a town in Moscow Oblast, Russia. Being under immediate jurisdiction of Moscow Oblast it is situated on the territory of Taldomsky Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending 
Element 117, ununseptium, has not yet been created or discovered, although its place in the periodic table is preestablished. Ununseptium (ˌjuːnənˈsɛptiəm or /ˌʌnənˈsɛptiəm/ is the temporary name of an undiscovered Chemical element in the Periodic table that has the temporary
According to Amnon Marinov and six other researchers element 122 has been detected naturally occurring in a thorium deposit. |-||-| Unbibium (ənˈbɪbiəm or Eka - Thorium is the temporary name of a (purportedly recently , this is the first Naturally occurring heavy element in more than 50 years. It has yet to be proved as it is still under confirmation by the university but could be a major development as previously all transuranic elements were artificial.