"fillings in permanent (adult) teeth. Mercury (element) Mercury is a chemical element with symbol Hg and atomic number 80. It is commonly known as quicksilver and was formerly named hydrargyrum ( ). A heavy, silvery d-block element, mercury is the only metallic element that is liquid at standard conditions for temperature and pressure; the only other element that is liquid under these conditions is bromine, though metals such as caesium, gallium, and rubidium melt just above room temperature. Mercury occurs in deposits throughout the world mostly as cinnabar (mercuric sulfide). The red pigment vermilion is obtained by grinding natural cinnabar"
"Hydrogen Hydrogen is a chemical element with symbol H and atomic number 1. With a standard atomic weight of , hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemical substance in the Universe, constituting roughly 75% of all baryonic mass. Non-remnant stars are mainly composed of hydrogen in the plasma state. The most common isotope of hydrogen, termed ""protium"" (name rarely used, symbol H), has one proton and no neutrons. The universal emergence of atomic hydrogen first occurred during the recombination epoch. At standard temperature and pressure, hydrogen is a colorless,"
"hot, is almost invisible, and thus can lead to accidental burns. Even interpreting the hydrogen data (including safety data) is confounded by a number of phenomena. Many physical and chemical properties of hydrogen depend on the parahydrogen/orthohydrogen ratio (it often takes days or weeks at a given temperature to reach the equilibrium ratio, for which the data is usually given). Hydrogen detonation parameters, such as critical detonation pressure and temperature, strongly depend on the container geometry. Hydrogen Hydrogen is a chemical element with symbol H and atomic number 1. With a standard atomic weight of , hydrogen is the lightest"
"molybdenum hexacarbonyl, and tungsten hexacarbonyl, seaborgium has been shown in 2014 to also form seaborgium hexacarbonyl, Sg(CO). Like its molybdenum and tungsten homologues, seaborgium hexacarbonyl is a volatile compound that reacts readily with silicon dioxide. Seaborgium Seaborgium is a synthetic chemical element with symbol Sg and atomic number 106. It is named after the American nuclear chemist Glenn T. Seaborg. As a synthetic element, it can be created in a laboratory but is not found in nature. It is also radioactive; the most stable known isotope, Sg, has a half-life of approximately 14 minutes. In the periodic table of the"
"Hassium Hassium is a synthetic chemical element with symbol Hs and atomic number 108. It is named after the German state of Hesse. It is a synthetic element and radioactive; the most stable known isotope, Hs, has a half-life of approximately 10 seconds. In the periodic table of the elements, it is a d-block transactinide element. Hassium is a member of the 7th period and belongs to the group 8 elements: it is thus the sixth member of the 6d series of transition metals. Chemistry experiments have confirmed that hassium behaves as the heavier homologue to osmium in group 8."
"Nh and Nh, which have already received preliminary chemical investigations. Roentgenium Roentgenium is a chemical element with symbol Rg and atomic number 111. It is an extremely radioactive synthetic element that can be created in a laboratory but is not found in nature. The most stable known isotope, roentgenium-282, has a half-life of 100 seconds, although the unconfirmed roentgenium-286 may have a longer half-life of about 10.7 minutes. Roentgenium was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany. It is named after the physicist Wilhelm Röntgen (also spelled Roentgen), who discovered X-rays."
"Seaborgium Seaborgium is a synthetic chemical element with symbol Sg and atomic number 106. It is named after the American nuclear chemist Glenn T. Seaborg. As a synthetic element, it can be created in a laboratory but is not found in nature. It is also radioactive; the most stable known isotope, Sg, has a half-life of approximately 14 minutes. In the periodic table of the elements, it is a d-block transactinide element. It is a member of the 7th period and belongs to the group 6 elements as the fourth member of the 6d series of transition metals. Chemistry experiments"
"Bohrium Bohrium is a synthetic chemical element with symbol Bh and atomic number 107. It is named after Danish physicist Niels Bohr. As a synthetic element, it can be created in a laboratory but is not found in nature. It is radioactive: its most stable known isotope, Bh, has a half-life of approximately 61 seconds, though the unconfirmed Bh may have a longer half-life of about 690 seconds. In the periodic table of the elements, it is a d-block transactinide element. It is a member of the 7th period and belongs to the group 7 elements as the fifth member"
"mg/m over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set the same recommended exposure limit (REL). At levels of 50 mg/m, hafnium is immediately dangerous to life and health. Hafnium Hafnium is a chemical element with symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869, though it was not identified until 1923, by Coster and Hevesy, making it the last stable element to be discovered. Hafnium is named after ""Hafnia"","
"advantages for future radiochemical experiments. Although the heavy isotope Bh requires a rare and highly radioactive berkelium target for its product, the isotopes Bh, Bh, and Bh can be readily produced as daughters of more easily produced moscovium and nihonium isotopes. Bohrium Bohrium is a synthetic chemical element with symbol Bh and atomic number 107. It is named after Danish physicist Niels Bohr. As a synthetic element, it can be created in a laboratory but is not found in nature. It is radioactive: its most stable known isotope, Bh, has a half-life of approximately 61 seconds, though the unconfirmed Bh"
"for studio lights and projectors, ignition elements in lighters and torches, electron cathodes, scintillators, GTAW electrodes, and other things. Lanthanum carbonate is used as a phosphate binder in cases of renal failure. It is also an element in the 6th period and in the 4th group. Hafnium is a chemical element with the symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869. Hafnium was the penultimate stable isotope element to be discovered (rhenium was identified two years"
"Nihonium Nihonium is a synthetic chemical element with the symbol Nh and atomic number 113. It is extremely radioactive; its most stable known isotope, nihonium-286, has a half-life of about 10 seconds. In the periodic table, nihonium is a transactinide element in the p-block. It is a member of period 7 and group 13 (boron group). Nihonium was first reported to have been created in 2003 by a Russian–American collaboration at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, and in 2004 by a team of Japanese scientists at Riken in Wakō, Japan. The confirmation of their claims"
"Magnesium Magnesium is a chemical element with symbol Mg and atomic number 12. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column (group 2, or alkaline earth metals) of the periodic table: all group 2 elements have the same electron configuration in the outer electron shell and a similar crystal structure. Magnesium is the ninth most abundant element in the universe. It is produced in large, aging stars from the sequential addition of three helium nuclei to a carbon nucleus. When such stars explode as supernovas, much of"
"experiments done on the bromides of group 5 elements, including the superheavy dubnium. Nihonium Nihonium is a synthetic chemical element with the symbol Nh and atomic number 113. It is extremely radioactive; its most stable known isotope, nihonium-286, has a half-life of about 10 seconds. In the periodic table, nihonium is a transactinide element in the p-block. It is a member of period 7 and group 13 (boron group). Nihonium was first reported to have been created in 2003 by a Russian–American collaboration at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia, and in 2004 by a team"
"Hafnium Hafnium is a chemical element with symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869, though it was not identified until 1923, by Coster and Hevesy, making it the last stable element to be discovered. Hafnium is named after ""Hafnia"", the Latin name for Copenhagen, where it was discovered. Hafnium is used in filaments and electrodes. Some semiconductor fabrication processes use its oxide for integrated circuits at 45 nm and smaller feature lengths. Some superalloys"
"Helium Helium (from ) is a chemical element with symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas, the first in the noble gas group in the periodic table. Its boiling point is the lowest among all the elements. After hydrogen, helium is the second lightest and second most abundant element in the observable universe, being present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined. Its abundance is similar to this figure in the Sun and in Jupiter. This"
"\ce{y}]} &\ce Isotopes of hydrogen Hydrogen (H) has three naturally occurring isotopes, sometimes denoted H, H, and H. The first two of these are stable, while H has a half-life of 12.32 years. All heavier isotopes are synthetic and have a half-life less than one zeptosecond (10 second). Of these, H is the most stable, and H is the least. Hydrogen is the only element whose isotopes have different names that are in common use today. The H (or hydrogen-2) isotope is usually called deuterium, while the H (or hydrogen-3) isotope is usually called tritium. The symbols D and T"
"Holmium Holmium is a chemical element with symbol Ho and atomic number 67. Part of the lanthanide series, holmium is a rare-earth element. Holmium was discovered by Swedish chemist Per Theodor Cleve. Its oxide was first isolated from rare-earth ores in 1878. The element's name comes from ""Holmia"", the Latin name for the city of Stockholm. Elemental holmium is a relatively soft and malleable silvery-white metal. It is too reactive to be found uncombined in nature, but when isolated, is relatively stable in dry air at room temperature. However, it reacts with water and corrodes readily and also burns in"
"lithium and fluorine (appearing twice), or left floating above the other elements and not assigned to any group in the periodic table. Helium is almost always placed above neon (which is in the p-block) in the periodic table as a noble gas, although it is occasionally placed above beryllium due to their similar electron configuration. Hydrogen (H) is the chemical element with atomic number 1. At standard temperature and pressure, hydrogen is a colorless, odorless, nonmetallic, tasteless, highly flammable diatomic gas with the molecular formula H. With an atomic mass of 1.00794 amu, hydrogen is the lightest element. Hydrogen is"
"H) to 109 (unnilennium, Une). The list given in ISO 31-8:1992 was quoted from the 1998 IUPAC ""Green Book"" Quantities, Units and Symbols in Physical Chemistry and adds in some cases in parentheses the Latin name for information, where the standard symbol has no relation to the English name of the element. Since the 1992 edition of the standard was published, some elements with atomic number above 103 have been discovered and renamed. Symbols for chemical elements shall be written in roman (upright) type. The symbol is not followed by a full-stop. Examples: Attached subscripts or superscripts specifying a nucleotide"
"the 30 Doradus region in the Large Magellanic Cloud and NGC 604 in the Triangulum Galaxy. The term H II is pronounced ""H two"" by astronomers. ""H"" is the chemical symbol for hydrogen, and ""II"" is the Roman numeral for 2. It is customary in astronomy to use the Roman numeral I for neutral atoms, II for singly-ionised—H II is H in other sciences—III for doubly-ionised, e.g. O III is O, etc. H II, or H, consists of free protons. An H I region being neutral atomic hydrogen, and a molecular cloud being molecular hydrogen, H. In spoken discussion with"
"Oganesson Oganesson is a synthetic chemical element with symbol Og and atomic number 118. It was first synthesized in 2002 at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia by a joint team of Russian and American scientists. In December 2015, it was recognized as one of four new elements by the Joint Working Party of the international scientific bodies IUPAC and IUPAP. It was formally named on 28 November 2016. The name is in line with the tradition of honoring a scientist, in this case the nuclear physicist Yuri Oganessian, who has played a leading role in"
"Oxygen Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. By mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula . Diatomic oxygen gas constitutes 20.8% of the Earth's atmosphere. As compounds including oxides, the element"
"Group 8 element Group 8 is a group of chemical element in the periodic table. It consists of iron (Fe), ruthenium (Ru), osmium (Os) and hassium (Hs). They are all transition metals. Like other groups, the members of this family show patterns in electron configuration, especially in the outermost shells, resulting in trends in chemical behavior. ""Group 8"" is the modern IUPAC name for this group; the old style name was ""group VIIIB"" in the CAS, US system or ""group VIIIA"" in the old IUPAC, European system. Group 8 should not be confused with the old-style group name of ""VIIIA"""
"either called it ""element 108"", with the symbol of ""E108"", ""(108)"", or even simply ""108"", or used the proposed name ""hassium"". The name ""hassium"" was proposed by Peter Armbruster and his colleagues, the officially recognised German discoverers, in September 1992. It is derived from the Latin name ""Hassia"" for the German state of Hesse where the institute is located. In 1994, IUPAC Commission on Nomenclature of Inorganic Chemistry recommended that element 108 be named ""hahnium"" (Hn) after the German physicist Otto Hahn so that elements named after Hahn and Lise Meitner (meitnerium) would be next to each other, honoring their"
"Isotopes of hydrogen Hydrogen (H) has three naturally occurring isotopes, sometimes denoted H, H, and H. The first two of these are stable, while H has a half-life of 12.32 years. All heavier isotopes are synthetic and have a half-life less than one zeptosecond (10 second). Of these, H is the most stable, and H is the least. Hydrogen is the only element whose isotopes have different names that are in common use today. The H (or hydrogen-2) isotope is usually called deuterium, while the H (or hydrogen-3) isotope is usually called tritium. The symbols D and T are sometimes"
"Group 12 element Group 12, by modern IUPAC numbering, is a group of chemical elements in the periodic table. It includes zinc (Zn), cadmium (Cd) and mercury (Hg). The further inclusion of copernicium (Cn) in group 12 is supported by recent experiments on individual copernicium atoms. Formerly this group was named ""IIB"" (pronounced as ""group two B"", as the ""II"" is a Roman numeral) by CAS and old IUPAC system. The three group 12 elements that occur naturally are zinc, cadmium and mercury. They are all widely used in electric and electronic applications, as well as in various alloys. The"
"Roentgenium Roentgenium is a chemical element with symbol Rg and atomic number 111. It is an extremely radioactive synthetic element that can be created in a laboratory but is not found in nature. The most stable known isotope, roentgenium-282, has a half-life of 100 seconds, although the unconfirmed roentgenium-286 may have a longer half-life of about 10.7 minutes. Roentgenium was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt, Germany. It is named after the physicist Wilhelm Röntgen (also spelled Roentgen), who discovered X-rays. In the periodic table, it is a d-block transactinide element."
"not flammable. According to IUPAC convention, by precedence (stylized electronegativity), hydrogen falls between group 15 and group 16 elements. Therefore, we have NH, 'nitrogen hydride' (ammonia), versus HO, 'hydrogen oxide' (water). This convention is sometimes broken for polonium, which on the grounds of polonium's metallicity is often referred to as 'polonium hydride' instead of the expected 'hydrogen polonide'. W. M. Mueller, J. P. Blackledge, G. G. Libowitz, ""Metal Hydrides"", Academic Press, N.Y. and London, (1968) Hydride In chemistry, a hydride is the anion of hydrogen, H, or, more commonly, it is a compound in which one or more hydrogen centres"
"Fermium Fermium is a synthetic element with symbol Fm and atomic number 100. It is an actinide and the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic quantities, although pure fermium metal has not yet been prepared. A total of 19 isotopes are known, with Fm being the longest-lived with a half-life of 100.5 days. It was discovered in the debris of the first hydrogen bomb explosion in 1952, and named after Enrico Fermi, one of the pioneers of nuclear physics. Its chemistry is typical"
"Pseudo palladium Pseudo palladium (RhAg) is a binary alloy consisting of equal parts of rhodium (atomic number 45) and silver (atomic number 47) created using nanotechnology to create a far more homogeneous mixture than might be possible using more conventional methods. This alloy exhibits properties of the intervening element palladium (atomic number 46). The production of this alloy was first reported by Kyoto University Professor Hiroshi Kitagawa and his research team, October 27, 2010. To make the new alloy, the Kyoto team used nanotechnology to ""nebulise"" the rhodium and silver and gradually mixed them with heated alcohol, with the two"
"fats, and aromatic esters, carotenoids and terpenes. With nitrogen it forms alkaloids, and with the addition of sulfur also it forms antibiotics, amino acids, and rubber products. With the addition of phosphorus to these other elements, it forms DNA and RNA, the chemical-code carriers of life, and adenosine triphosphate (ATP), the most important energy-transfer molecule in all living cells. Nitrogen is the chemical element with atomic number 7, the symbol N and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere. The element"
"GdGaO, GaH, GaBr, GaCl, GaF, Ga(OH), Ga(NO), GaN, GaO, GaP, Ga(SO), GaS, Ga(CH) GeH, GeCl, GeI, GeO, GeSe, GeS, GeS, GeCl, GeF, Ge(CH), (CH)GeCl HAuCl, (PhP)AuCl, AuBr, AuCl, AuCl, AuO, AuS, KAu(CN) HfC, HfO, HfCl, CpHfCl Hs, HsONa<nowiki>[</nowiki>HsO(OH)<nowiki>]</nowiki> He, HeH No neutral compounds known. Ho(CO), HoCl, HoF, Ho(NO), HoO, HoPO, Ho(SO), ""Only simple and common hydrides are listed here. For hydroxides of metals, see the appropriate metal. For ammonium compounds, see #Nitrogen."" AlH, NH, AsH, BeH, BiH, HBO, HBrO, CaH, HCBH, HClO, HClO, BH, NH, PH, HBF, GaH, GeH, HSbF, HPF, HSiF, HTiF, NH, HN, HBr(aq), HCl(aq), HCN, HF(aq) HBr,"