222 relations: Abundance of the chemical elements, Alkaline earth metal, Alpha particle, Aluminate, Aluminium, Ammonia, Analytical chemistry, Ancient Rome, Angular momentum, Anhydrite, Anisotropy, Antacid, Antimony, Antoine Lavoisier, Apatite, Aragonite, Argon, Aspartic acid, Atomic number, Automotive battery, Barium, Beryllium, Beta decay, Bicarbonate, Biochemistry, Bismuth, Blood vessel, Calcification, Calcite, Calcitonin, Calcium acetate, Calcium carbonate, Calcium chloride, Calcium hydride, Calcium hydroxide, Calcium lactate, Calcium nitride, Calcium oxide, Calcium pyrophosphate, Calcium silicate, Calcium sulfate, Calcium sulfite, Calcium-48, Canada, Carbon, Carbon cycle, Carbon dioxide, Carbonate, Carboxylic acid, Cast iron, ..., Catalysis, Cell (biology), Cell membrane, Chalk, Chelation, Chemical affinity, Chemical element, China, Chromium, Climate, Close-packing of equal spheres, Cofactor (biochemistry), Coordination complex, Copper, Coral, Cosmogenic nuclide, Cubic crystal system, Cyclopentadiene, Cyclopentadienyl, Denticity, Dicalcium phosphate, Dietary Reference Intake, Disproportionation, Divalent, Dolomite, Double beta decay, Electrolysis, Electrolyte, Electron capture, Electron configuration, Enzyme, Ethylenediaminetetraacetic acid, European Food Safety Authority, Europium, Even and odd atomic nuclei, Extinct radionuclide, Fertilisation, Florida Keys, Fluorite, Forbidden mechanism, France, Geology of the Moon, Getter, Glutamic acid, Great Pyramid of Giza, Group 2 organometallic chemistry, Gypsum, Hard water, Hexagonal crystal family, Humphry Davy, Hydroxylapatite, Hypercalcaemia, Hypocalcaemia, Iceland spar, Intermetallic, Ionic compound, Ionic radius, Iron, Isotope, Isotope fractionation, Jöns Jacob Berzelius, Joseph Black, Journal of the American Chemical Society, Khafajah, Lactobionic acid, Lanthanide, Lathe, Latin, Lattice energy, Lead, Leavening agent, Lime (material), Lime kiln, Lime plaster, Limestone, Lithosphere, Macrocycle, Magic number (physics), Magnesium, Marble, Menopause, Mercury(II) oxide, Mesopotamia, Metastasis, Mineral (nutrient), Molar concentration, Monocalcium phosphate, Muscle, Neuron, Neurotransmitter, Neutrino Ettore Majorana Observatory, Neutron activation, Neutron emission, Nitrogen, Noble gas, Nuclear drip line, Nuclear Physics (journal), Orthorhombic crystal system, Osteocalcin, Osteomalacia, Osteopontin, Osteoporosis, Oxygen, Oxygen-burning process, Parathyroid hormone, Pearl, Periodic Videos, Peroxide, PH, Phospholipid, Phosphorylation, Physical Review, Physiology, Platinum, Polyphosphate, Positron emission, Post-transition metal, Potassium, Potassium-40, Primordial nuclide, Protein, Proton emission, R-process, Radical ion, Radionuclide, Radium, Red Sea, Relative humidity, Russia, S-process, Saponification, Scandium, Seashell, Second messenger system, Sedimentary rock, Serine, Signal transduction, Silicon-burning process, Skeleton, Solid, Spin (physics), Standard enthalpy of formation, Steelmaking, Steric effects, Strontium, Sulfur, Superoxide, Tectonics, Tetany, The Bahamas, Thorium, Threonine, Thrombosis, Titanium, Tonne, Toothpaste, Total inorganic carbon, Tricalcium phosphate, Trypsin, Tutankhamun, Type Ia supernova, Tyrosine, United States, Uranium, Valence electron, Vitamin D, Vitruvius, Voltage, Vulnerable plaque, Ytterbium, Zinc, Zirconium. Expand index (172 more) » « Shrink index
The abundance of the chemical elements is a measure of the occurrence of the chemical elements relative to all other elements in a given environment.
The alkaline earth metals are six chemical elements in group 2 of the periodic table.
Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus.
In chemistry aluminate is a compound containing an oxyanion of aluminium, such as sodium aluminate.
Aluminium or aluminum is a chemical element with symbol Al and atomic number 13.
Ammonia is a compound of nitrogen and hydrogen with the formula NH3.
Analytical chemistry studies and uses instruments and methods used to separate, identify, and quantify matter.
In historiography, ancient Rome is Roman civilization from the founding of the city of Rome in the 8th century BC to the collapse of the Western Roman Empire in the 5th century AD, encompassing the Roman Kingdom, Roman Republic and Roman Empire until the fall of the western empire.
In physics, angular momentum (rarely, moment of momentum or rotational momentum) is the rotational equivalent of linear momentum.
Anhydrite is a mineral—anhydrous calcium sulfate, CaSO4.
Anisotropy, is the property of being directionally dependent, which implies different properties in different directions, as opposed to isotropy.
An antacid is a substance which neutralizes stomach acidity and is used to relieve heartburn, indigestion or an upset stomach.
Antimony is a chemical element with symbol Sb (from stibium) and atomic number 51.
Antoine-Laurent de Lavoisier (also Antoine Lavoisier after the French Revolution;; 26 August 17438 May 1794) CNRS (Centre National de la Recherche Scientifique) was a French nobleman and chemist who was central to the 18th-century chemical revolution and who had a large influence on both the history of chemistry and the history of biology.
Apatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ions, respectively, in the crystal.
Aragonite is a carbonate mineral, one of the two most common, naturally occurring, crystal forms of calcium carbonate, CaCO3 (the other forms being the minerals calcite and vaterite).
Argon is a chemical element with symbol Ar and atomic number 18.
Aspartic acid (symbol Asp or D; salts known as aspartates), is an α-amino acid that is used in the biosynthesis of proteins.
The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of an atom.
An automotive battery is a rechargeable battery that supplies electrical current to a motor vehicle.
Barium is a chemical element with symbol Ba and atomic number 56.
Beryllium is a chemical element with symbol Be and atomic number 4.
In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which a beta ray (fast energetic electron or positron) and a neutrino are emitted from an atomic nucleus.
In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid.
Biochemistry, sometimes called biological chemistry, is the study of chemical processes within and relating to living organisms.
Bismuth is a chemical element with symbol Bi and atomic number 83.
The blood vessels are the part of the circulatory system, and microcirculation, that transports blood throughout the human body.
Calcification is the accumulation of calcium salts in a body tissue.
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3).
Calcitonin (also known as thyrocalcitonin) is a 32-amino acid linear polypeptide hormone that is produced in humans primarily by the parafollicular cells (also known as C-cells) of the thyroid gland, and in many other animals in the ultimopharyngeal body.
Calcium acetate is a chemical compound which is a calcium salt of acetic acid.
Calcium carbonate is a chemical compound with the formula CaCO3.
Calcium chloride is an inorganic compound, a salt with the chemical formula CaCl2.
Calcium hydride is the chemical compound with the formula CaH2, and is therefore an alkaline earth hydride.
Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca(OH)2.
Calcium lactate is a white crystalline salt with formula, consisting of two lactate anions (CHOH) for each calcium cation.
Calcium nitride is the inorganic compound with the chemical formula Ca3N2.
Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound.
Calcium pyrophosphate (Ca2P2O7) is a chemical compound, an insoluble calcium salt containing the pyrophosphate anion.
Calcium silicate is the chemical compound Ca2SiO4, also known as calcium orthosilicate and is sometimes formulated as 2CaO·SiO2.
Calcium sulfate (or calcium sulphate) is the inorganic compound with the formula CaSO4 and related hydrates.
Calcium sulfite, or calcium sulphite, is a chemical compound, the calcium salt of sulfite with the formula CaSO3·x(H2O).
Calcium-48 is a scarce isotope of calcium containing 20 protons and 28 neutrons.
Canada is a country located in the northern part of North America.
Carbon (from carbo "coal") is a chemical element with symbol C and atomic number 6.
The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth.
Carbon dioxide (chemical formula) is a colorless gas with a density about 60% higher than that of dry air.
In chemistry, a carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula of.
A carboxylic acid is an organic compound that contains a carboxyl group (C(.
Cast iron is a group of iron-carbon alloys with a carbon content greater than 2%.
Catalysis is the increase in the rate of a chemical reaction due to the participation of an additional substance called a catalysthttp://goldbook.iupac.org/C00876.html, which is not consumed in the catalyzed reaction and can continue to act repeatedly.
The cell (from Latin cella, meaning "small room") is the basic structural, functional, and biological unit of all known living organisms.
The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates the interior of all cells from the outside environment (the extracellular space).
Chalk is a soft, white, porous, sedimentary carbonate rock, a form of limestone composed of the mineral calcite.
Chelation is a type of bonding of ions and molecules to metal ions.
In chemical physics and physical chemistry, chemical affinity is the electronic property by which dissimilar chemical species are capable of forming chemical compounds.
A chemical element is a species of atoms having the same number of protons in their atomic nuclei (that is, the same atomic number, or Z).
China, officially the People's Republic of China (PRC), is a unitary one-party sovereign state in East Asia and the world's most populous country, with a population of around /1e9 round 3 billion.
Chromium is a chemical element with symbol Cr and atomic number 24.
Climate is the statistics of weather over long periods of time.
In geometry, close-packing of equal spheres is a dense arrangement of congruent spheres in an infinite, regular arrangement (or lattice).
A cofactor is a non-protein chemical compound or metallic ion that is required for an enzyme's activity.
In chemistry, a coordination complex consists of a central atom or ion, which is usually metallic and is called the coordination centre, and a surrounding array of bound molecules or ions, that are in turn known as ligands or complexing agents.
Copper is a chemical element with symbol Cu (from cuprum) and atomic number 29.
Corals are marine invertebrates in the class Anthozoa of phylum Cnidaria.
Cosmogenic nuclides (or cosmogenic isotopes) are rare nuclides (isotopes) created when a high-energy cosmic ray interacts with the nucleus of an in situ Solar System atom, causing nucleons (protons and neutrons) to be expelled from the atom (see cosmic ray spallation).
In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube.
Cyclopentadiene is an organic compound with the formula C5H6.
Cyclopentadienyl can refer to.
Denticity refers to the number of donor groups in a single ligand that bind to a central atom in a coordination complex.
Dicalcium phosphate is the calcium phosphate with the formula CaHPO4 and its dihydrate. The "di" prefix in the common name arises because the formation of the HPO42– anion involves the removal of two protons from phosphoric acid, H3PO4. It is also known as dibasic calcium phosphate or calcium monohydrogen phosphate. Dicalcium phosphate is used as a food additive, it is found in some toothpastes as a polishing agent and is a biomaterial.
The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the Institute of Medicine (IOM) of the National Academies (United States).
Disproportionation, sometimes called dismutation, is a redox reaction in which a compound of intermediate oxidation state converts to two different compounds, one of higher and one of lower oxidation states.
In chemistry, a divalent (sometimes bivalent) element, ion, functional group, or molecule has a valence of two.
Dolomite is an anhydrous carbonate mineral composed of calcium magnesium carbonate, ideally The term is also used for a sedimentary carbonate rock composed mostly of the mineral dolomite.
In nuclear physics, double beta decay is a type of radioactive decay in which two protons are simultaneously transformed into two neutrons, or vice versa, inside an atomic nucleus.
In chemistry and manufacturing, electrolysis is a technique that uses a direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction.
An electrolyte is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water.
Electron capture (K-electron capture, also K-capture, or L-electron capture, L-capture) is a process in which the proton-rich nucleus of an electrically neutral atom absorbs an inner atomic electron, usually from the K or L electron shell.
In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals.
Enzymes are macromolecular biological catalysts.
Ethylenediaminetetraacetic acid (EDTA), also known by several other names, is a chemical originating in multiseasonal plants with dormancy stages as a lipidopreservative which helps to develop the stem, currently used for both industrial and medical purposes.
The European Food Safety Authority (EFSA) is the agency of the European Union (EU) that provides independent scientific advice and communicates on existing and emerging risks associated with the food chain.
Europium is a chemical element with symbol Eu and atomic number 63.
In nuclear physics, properties of a nucleus depend on evenness or oddness of its atomic number Z, neutron number N and, consequently, of their sum, the mass number A. Most notably, oddness of both Z and N tends to lower the nuclear binding energy, making odd nuclei, generally, less stable.
An extinct radionuclide is a radionuclide that was formed by nucleosynthesis before the formation of the Solar System, about 4.6 billion years ago, and incorporated into it, but has since decayed to virtually zero abundance, due to having a half-life shorter than about 100 million years.
Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, conception, fecundation, syngamy and impregnation, is the fusion of gametes to initiate the development of a new individual organism.
The Florida Keys are a coral cay archipelago located off the southern coast of Florida, forming the southernmost portion of the continental United States.
Not to be confused with Fluoride. Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF2.
In spectroscopy, a forbidden mechanism (forbidden transition or forbidden line) is a spectral line associated with absorption or emission of light by atomic nuclei, atoms, or molecules which undergo a transition that is not allowed by a particular selection rule but is allowed if the approximation associated with that rule is not made.
France, officially the French Republic (République française), is a sovereign state whose territory consists of metropolitan France in Western Europe, as well as several overseas regions and territories.
The geology of the Moon (sometimes called selenology, although the latter term can refer more generally to "lunar science") is quite different from that of Earth.
A getter is a deposit of reactive material that is placed inside a vacuum system, for the purpose of completing and maintaining the vacuum.
Glutamic acid (symbol Glu or E) is an α-amino acid with formula.
The Great Pyramid of Giza (also known as the Pyramid of Khufu or the Pyramid of Cheops) is the oldest and largest of the three pyramids in the Giza pyramid complex bordering what is now El Giza, Egypt.
The group 2 elements are known to form organometallic compounds.
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O.
Hard water is water that has high mineral content (in contrast with "soft water").
In crystallography, the hexagonal crystal family is one of the 6 crystal families, which includes 2 crystal systems (hexagonal and trigonal) and 2 lattice systems (hexagonal and rhombohedral).
Sir Humphry Davy, 1st Baronet (17 December 177829 May 1829) was a Cornish chemist and inventor, who is best remembered today for isolating, using electricity, a series of elements for the first time: potassium and sodium in 1807 and calcium, strontium, barium, magnesium and boron the following year, as well as discovering the elemental nature of chlorine and iodine.
Hydroxylapatite, also called hydroxyapatite (HA), is a naturally occurring mineral form of calcium apatite with the formula Ca5(PO4)3(OH), but is usually written Ca10(PO4)6(OH)2 to denote that the crystal unit cell comprises two entities.
Hypercalcaemia, also spelled hypercalcemia, is a high calcium (Ca2+) level in the blood serum.
Hypocalcaemia, also spelled hypocalcemia, is low calcium levels in the blood serum.
Iceland spar, formerly known as Iceland crystal (silfurberg; lit. silver-rock), is a transparent variety of calcite, or crystallized calcium carbonate, originally brought from Iceland, and used in demonstrating the polarization of light (see polarimetry).
An intermetallic (also called an intermetallic compound, intermetallic alloy, ordered intermetallic alloy, and a long-range-ordered alloy) is a solid-state compound exhibiting metallic bonding, defined stoichiometry and ordered crystal structure.
In chemistry, an ionic compound is a chemical compound composed of ions held together by electrostatic forces termed ionic bonding.
Ionic radius, rion, is the radius of an atom's ion in ionic crystals structure.
Iron is a chemical element with symbol Fe (from ferrum) and atomic number 26.
Isotopes are variants of a particular chemical element which differ in neutron number.
Isotope fractionation describes processes that affect the relative abundance of isotopes, often used in isotope geochemistry.
Baron Jöns Jacob Berzelius (20 August 1779 – 7 August 1848), named by himself and contemporary society as Jacob Berzelius, was a Swedish chemist.
Joseph Black FRSE FRCPE FPSG (16 April 1728 – 6 December 1799) was a Scottish physician and chemist, known for his discoveries of magnesium, latent heat, specific heat, and carbon dioxide.
The Journal of the American Chemical Society (also known as JACS) is a weekly peer-reviewed scientific journal that was established in 1879 by the American Chemical Society.
Khafajah or Khafaje (ancient Tutub) is an archaeological site in Diyala Province (Iraq).
Lactobionic acid (4-O-β-galactopyranosyl-D-gluconic acid) is a sugar acid.
The lanthanide or lanthanoid series of chemical elements comprises the 15 metallic chemical elements with atomic numbers 57 through 71, from lanthanum through lutetium.
A lathe is a tool that rotates the workpiece about an axis of rotation to perform various operations such as cutting, sanding, knurling, drilling, deformation, facing, and turning, with tools that are applied to the workpiece to create an object with symmetry about that axis.
Latin (Latin: lingua latīna) is a classical language belonging to the Italic branch of the Indo-European languages.
The lattice energy of a crystalline solid is often defined as the energy of formation of a crystal from infinitely-separated ions and as such is invariably negative.
Lead is a chemical element with symbol Pb (from the Latin plumbum) and atomic number 82.
A leaven, often called a leavening agent (and also known as a raising agent), is any one of a number of substances used in doughs and batters that cause a foaming action (gas bubbles) that lightens and softens the mixture.
Lime is a calcium-containing inorganic mineral in which oxides, and hydroxides predominate.
A lime kiln is a kiln used for the calcination of limestone (calcium carbonate) to produce the form of lime called quicklime (calcium oxide).
Lime plaster is a type of plaster composed of sand, water, and lime, usually non-hydraulic hydrated lime (also known as slaked lime, high calcium lime or air lime).
Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral, forams and molluscs.
A lithosphere (λίθος for "rocky", and σφαίρα for "sphere") is the rigid, outermost shell of a terrestrial-type planet, or natural satellite, that is defined by its rigid mechanical properties.
Macrocycles are often described as a molecule containing twelve or more atoms with at least one large ring.
In nuclear physics, a magic number is a number of nucleons (either protons or neutrons, separately) such that they are arranged into complete shells within the atomic nucleus.
Magnesium is a chemical element with symbol Mg and atomic number 12.
Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite.
Menopause, also known as the climacteric, is the time in most women's lives when menstrual periods stop permanently, and they are no longer able to bear children.
Mercury(II) oxide, also called mercuric oxide or simply mercury oxide, has a formula of HgO.
Mesopotamia is a historical region in West Asia situated within the Tigris–Euphrates river system, in modern days roughly corresponding to most of Iraq, Kuwait, parts of Northern Saudi Arabia, the eastern parts of Syria, Southeastern Turkey, and regions along the Turkish–Syrian and Iran–Iraq borders.
Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; it is typically spoken of as such spread by a cancerous tumor.
In the context of nutrition, a mineral is a chemical element required as an essential nutrient by organisms to perform functions necessary for life.
Molar concentration (also called molarity, amount concentration or substance concentration) is a measure of the concentration of a chemical species, in particular of a solute in a solution, in terms of amount of substance per unit volume of solution.
Monocalcium phosphate is an inorganic compound with the chemical formula Ca(H2PO4)2 ("ACMP" or "CMP-A" for anhydrous monocalcium phosphate).
Muscle is a soft tissue found in most animals.
A neuron, also known as a neurone (British spelling) and nerve cell, is an electrically excitable cell that receives, processes, and transmits information through electrical and chemical signals.
Neurotransmitters are endogenous chemicals that enable neurotransmission.
The Neutrino Ettore Majorana Observatory (NEMO experiment) is an international collaboration of scientists searching for neutrinoless double beta decay (0νββ).
Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states.
Neutron emission is a mode of radioactive decay in which one or more neutrons are ejected from a nucleus.
Nitrogen is a chemical element with symbol N and atomic number 7.
The noble gases (historically also the inert gases) make up a group of chemical elements with similar properties; under standard conditions, they are all odorless, colorless, monatomic gases with very low chemical reactivity.
The nuclear drip line is the boundary delimiting the zone beyond which atomic nuclei decay by the emission of a proton or neutron.
Nuclear Physics is a peer-reviewed scientific journal published by Elsevier.
In crystallography, the orthorhombic crystal system is one of the 7 crystal systems.
Osteocalcin, also known as bone gamma-carboxyglutamic acid-containing protein (BGLAP), is a noncollagenous protein hormone found in bone and dentin.
Osteomalacia is the softening of the bones caused by impaired bone metabolism primarily due to inadequate levels of available phosphate, calcium, and vitamin D, or because of resorption of calcium.
Osteopontin (OPN), also known as bone sialoprotein I (BSP-1 or BNSP), early T-lymphocyte activation (ETA-1), secreted phosphoprotein 1 (SPP1), 2ar and Rickettsia resistance (Ric), is a protein that in humans is encoded by the SPP1 gene (secreted phosphoprotein 1).
Osteoporosis is a disease where increased bone weakness increases the risk of a broken bone.
Oxygen is a chemical element with symbol O and atomic number 8.
The oxygen-burning process is a set of nuclear fusion reactions that take place in massive stars that have used up the lighter elements in their cores.
Parathyroid hormone (PTH), also called parathormone or parathyrin, is a hormone secreted by the parathyroid glands that is important in bone remodeling, which is an ongoing process in which bone tissue is alternately resorbed and rebuilt over time.
A pearl is a hard glistening object produced within the soft tissue (specifically the mantle) of a living shelled mollusk or another animal, such as a conulariid.
The Periodic Table of Videos (usually shortened to Periodic Videos) is a series of videos about chemical elements and the periodic table.
Peroxide is a compound with the structure R-O-O-R. The O−O group in a peroxide is called the peroxide group or peroxo group.
In chemistry, pH is a logarithmic scale used to specify the acidity or basicity of an aqueous solution.
Phospholipids are a class of lipids that are a major component of all cell membranes.
In chemistry, phosphorylation of a molecule is the attachment of a phosphoryl group.
Physical Review is an American peer-reviewed scientific journal established in 1893 by Edward Nichols.
Physiology is the scientific study of normal mechanisms, and their interactions, which work within a living system.
Platinum is a chemical element with symbol Pt and atomic number 78.
Polyphosphates are salts or esters of polymeric oxyanions formed from tetrahedral PO4 (phosphate) structural units linked together by sharing oxygen atoms.
Positron emission or beta plus decay (β+ decay) is a subtype of radioactive decay called beta decay, in which a proton inside a radionuclide nucleus is converted into a neutron while releasing a positron and an electron neutrino (νe).
Post-transition metals are a set of metallic elements in the periodic table located between the transition metals to their left, and the metalloids to their right.
Potassium is a chemical element with symbol K (from Neo-Latin kalium) and atomic number 19.
Potassium-40 (40K) is a radioactive isotope of potassium which has a very long half-life of 1.251 years.
In geochemistry, geophysics and geonuclear physics, primordial nuclides, also known as primordial isotopes, are nuclides found on Earth that have existed in their current form since before Earth was formed.
Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues.
Proton emission (also known as proton radioactivity) is a rare type of radioactive decay in which a proton is ejected from a nucleus.
The rapid neutron-capture process, or so-called r-process, is a set of nuclear reactions that in nuclear astrophysics is responsible for the creation (nucleosynthesis) of approximately half the abundances of the atomic nuclei heavier than iron, usually synthesizing the entire abundance of the two most neutron-rich stable isotopes of each heavy element.
A radical ion is a free radical species that carries a charge.
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is an atom that has excess nuclear energy, making it unstable.
Radium is a chemical element with symbol Ra and atomic number 88.
The Red Sea (also the Erythraean Sea) is a seawater inlet of the Indian Ocean, lying between Africa and Asia.
Relative humidity (RH) is the ratio of the partial pressure of water vapor to the equilibrium vapor pressure of water at a given temperature.
Russia (rɐˈsʲijə), officially the Russian Federation (p), is a country in Eurasia. At, Russia is the largest country in the world by area, covering more than one-eighth of the Earth's inhabited land area, and the ninth most populous, with over 144 million people as of December 2017, excluding Crimea. About 77% of the population live in the western, European part of the country. Russia's capital Moscow is one of the largest cities in the world; other major cities include Saint Petersburg, Novosibirsk, Yekaterinburg and Nizhny Novgorod. Extending across the entirety of Northern Asia and much of Eastern Europe, Russia spans eleven time zones and incorporates a wide range of environments and landforms. From northwest to southeast, Russia shares land borders with Norway, Finland, Estonia, Latvia, Lithuania and Poland (both with Kaliningrad Oblast), Belarus, Ukraine, Georgia, Azerbaijan, Kazakhstan, China, Mongolia and North Korea. It shares maritime borders with Japan by the Sea of Okhotsk and the U.S. state of Alaska across the Bering Strait. The East Slavs emerged as a recognizable group in Europe between the 3rd and 8th centuries AD. Founded and ruled by a Varangian warrior elite and their descendants, the medieval state of Rus arose in the 9th century. In 988 it adopted Orthodox Christianity from the Byzantine Empire, beginning the synthesis of Byzantine and Slavic cultures that defined Russian culture for the next millennium. Rus' ultimately disintegrated into a number of smaller states; most of the Rus' lands were overrun by the Mongol invasion and became tributaries of the nomadic Golden Horde in the 13th century. The Grand Duchy of Moscow gradually reunified the surrounding Russian principalities, achieved independence from the Golden Horde. By the 18th century, the nation had greatly expanded through conquest, annexation, and exploration to become the Russian Empire, which was the third largest empire in history, stretching from Poland on the west to Alaska on the east. Following the Russian Revolution, the Russian Soviet Federative Socialist Republic became the largest and leading constituent of the Union of Soviet Socialist Republics, the world's first constitutionally socialist state. The Soviet Union played a decisive role in the Allied victory in World War II, and emerged as a recognized superpower and rival to the United States during the Cold War. The Soviet era saw some of the most significant technological achievements of the 20th century, including the world's first human-made satellite and the launching of the first humans in space. By the end of 1990, the Soviet Union had the world's second largest economy, largest standing military in the world and the largest stockpile of weapons of mass destruction. Following the dissolution of the Soviet Union in 1991, twelve independent republics emerged from the USSR: Russia, Ukraine, Belarus, Kazakhstan, Uzbekistan, Armenia, Azerbaijan, Georgia, Kyrgyzstan, Moldova, Tajikistan, Turkmenistan and the Baltic states regained independence: Estonia, Latvia, Lithuania; the Russian SFSR reconstituted itself as the Russian Federation and is recognized as the continuing legal personality and a successor of the Soviet Union. It is governed as a federal semi-presidential republic. The Russian economy ranks as the twelfth largest by nominal GDP and sixth largest by purchasing power parity in 2015. Russia's extensive mineral and energy resources are the largest such reserves in the world, making it one of the leading producers of oil and natural gas globally. The country is one of the five recognized nuclear weapons states and possesses the largest stockpile of weapons of mass destruction. Russia is a great power as well as a regional power and has been characterised as a potential superpower. It is a permanent member of the United Nations Security Council and an active global partner of ASEAN, as well as a member of the G20, the Shanghai Cooperation Organisation (SCO), the Council of Europe, the Asia-Pacific Economic Cooperation (APEC), the Organization for Security and Co-operation in Europe (OSCE), and the World Trade Organization (WTO), as well as being the leading member of the Commonwealth of Independent States (CIS), the Collective Security Treaty Organization (CSTO) and one of the five members of the Eurasian Economic Union (EEU), along with Armenia, Belarus, Kazakhstan and Kyrgyzstan.
The slow neutron-capture process or s-process is a series of reactions in nuclear astrophysics that occur in stars, particularly AGB stars.
Saponification is a process that produces soap.
Scandium is a chemical element with symbol Sc and atomic number 21.
A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer created by an animal that lives in the sea.
Second messengers are intracellular signaling molecules released by the cell in response to exposure to extracellular signaling molecules—the first messengers.
Sedimentary rocks are types of rock that are formed by the deposition and subsequent cementation of that material at the Earth's surface and within bodies of water.
Serine (symbol Ser or S) is an ɑ-amino acid that is used in the biosynthesis of proteins.
Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinases, which ultimately results in a cellular response.
In astrophysics, silicon burning is a very brief sequence of nuclear fusion reactions that occur in massive stars with a minimum of about 8-11 solar masses.
The skeleton is the body part that forms the supporting structure of an organism.
Solid is one of the four fundamental states of matter (the others being liquid, gas, and plasma).
In quantum mechanics and particle physics, spin is an intrinsic form of angular momentum carried by elementary particles, composite particles (hadrons), and atomic nuclei.
The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements, with all substances in their standard states.
Steelmaking is the process for producing steel from iron ore and scrap.
Steric effects are nonbonding interactions that influence the shape (conformation) and reactivity of ions and molecules.
Strontium is the chemical element with symbol Sr and atomic number 38.
Sulfur or sulphur is a chemical element with symbol S and atomic number 16.
A superoxide is a compound that contains the superoxide anion, which has the chemical formula.
Tectonics is the process that controls the structure and properties of the Earth's crust and its evolution through time.
Tetany or tetany seizure is a medical sign consisting of the involuntary contraction of muscles, which may be caused by disease or other conditions that increase the action potential frequency of muscle cells or the nerves that innervate them.
The Bahamas, known officially as the Commonwealth of The Bahamas, is an archipelagic state within the Lucayan Archipelago.
Thorium is a weakly radioactive metallic chemical element with symbol Th and atomic number 90.
Threonine (symbol Thr or T) is an amino acid that is used in the biosynthesis of proteins.
Thrombosis (from Ancient Greek θρόμβωσις thrómbōsis "clotting”) is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system.
Titanium is a chemical element with symbol Ti and atomic number 22.
The tonne (Non-SI unit, symbol: t), commonly referred to as the metric ton in the United States, is a non-SI metric unit of mass equal to 1,000 kilograms;.
Toothpaste is a paste or gel dentifrice used with a toothbrush as an accessory to clean and maintain the aesthetics and health of teeth.
The total inorganic carbon (CT, or TIC) or dissolved inorganic carbon (DIC) is the sum of inorganic carbon species in a solution.
Tricalcium phosphate (sometimes abbreviated TCP) is a calcium salt of phosphoric acid with the chemical formula Ca3(PO4)2.
Trypsin is a serine protease from the PA clan superfamily, found in the digestive system of many vertebrates, where it hydrolyzes proteins.
Tutankhamun (alternatively spelled with Tutenkh-, -amen, -amon) was an Egyptian pharaoh of the 18th dynasty (ruled c. 1332–1323 BC in the conventional chronology), during the period of Egyptian history known as the New Kingdom or sometimes the New Empire Period.
A type Ia supernova (read "type one-a") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf.
Tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins.
The United States of America (USA), commonly known as the United States (U.S.) or America, is a federal republic composed of 50 states, a federal district, five major self-governing territories, and various possessions.
Uranium is a chemical element with symbol U and atomic number 92.
In chemistry, a valence electron is an outer shell electron that is associated with an atom, and that can participate in the formation of a chemical bond if the outer shell is not closed; in a single covalent bond, both atoms in the bond contribute one valence electron in order to form a shared pair.
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and multiple other biological effects.
Marcus Vitruvius Pollio (c. 80–70 BC – after c. 15 BC), commonly known as Vitruvius, was a Roman author, architect, civil engineer and military engineer during the 1st century BC, known for his multi-volume work entitled De architectura.
Voltage, electric potential difference, electric pressure or electric tension (formally denoted or, but more often simply as V or U, for instance in the context of Ohm's or Kirchhoff's circuit laws) is the difference in electric potential between two points.
A vulnerable plaque is a kind of atheromatous plaque – a collection of white blood cells (primarily macrophages) and lipids (including cholesterol) in the wall of an artery – that is particularly unstable and prone to produce sudden major problems such as a heart attack or stroke.
Ytterbium is a chemical element with symbol Yb and atomic number 70.
Zinc is a chemical element with symbol Zn and atomic number 30.
Zirconium is a chemical element with symbol Zr and atomic number 40.