581 relations: Abundance of elements in Earth's crust, Abundance of the chemical elements, Acetylene, Acetylide, Acid–base reaction, Actinium, Action potential, Activation energy, Air conditioning, Alcohol, Aldehyde, Alkali, Alkali metal halide, Alkalide, Alkaline earth metal, Alkene, Alkoxide, Alkyne, Alpha decay, Alum, Aluminium, Aluminium hydroxide, American Chemical Society, Amide, Ammonia, Ammonium, Amphibole, Ancient Greek, Angewandte Chemie, Anhydrous, Annalen der Physik, Antimonide, Antimony, Antoine Lavoisier, Aqueous solution, Argon, Argonne National Laboratory, Arsenic, Arsonium, Astatine, Asterisk, Atom, Atomic clock, Atomic number, Atomic orbital, Atomic radius, Azide, Bad Dürkheim, Barium, Barn (unit), ..., Base (chemistry), BASF, Beryllium, Beta decay, Beta-decay stable isobars, Bicarbonate, Big Bang nucleosynthesis, Bipolar disorder, Bismuth, Bisulfide, Block (periodic table), Boiling point, Boride, Boron, Boron group, Bracket, Brazil, Breeder reactor, Brine, Bromine, Buckminsterfullerene, Butyllithium, Cadmium, Caesium, Caesium auride, Caesium chloride, Caesium-137, Calcium, Calcium chloride, Carbanion, Carbon, Carbon dioxide, Carbon group, Carbon monoxide, Carbonate, Carbonyl group, Carboxylic acid, Cardiac arrest, Carnallite, Catalysis, Cell (biology), Cell membrane, Centimetre, Central nervous system, Charge density, Chemical Abstracts Service, Chemical element, Chemical polarity, Chemical property, Chemical reaction, Chernobyl disaster, Chernobyl Exclusion Zone, Chernobyl Nuclear Power Plant, Chlorine, Cluster chemistry, Cobalt, Cobaltocene, Committee on Data for Science and Technology, Concentration, Congener (chemistry), Continental Europe, Coordinate covalent bond, Coordination complex, Coordination number, Coordination sphere, Copper, Coulomb explosion, Coupling constant, Covalent bond, Cross section (physics), Crown ether, Crust (geology), Cryolite, Cryptand, Crystal structure, Cubic crystal system, Curie Institute (Paris), Cyanide, Cyclooctatetraene, Cyclopentadiene, Dead Sea, Decamethylcobaltocene, Decay chain, Decay product, Dehumidifier, Deltahedron, Density, Desiccant, Diagonal relationship, Diamond cubic, Diatomic molecule, Dietary Reference Intake, Dilithium, Dipotassium cyclooctatetraenide, Dissociation (chemistry), Dmitri Mendeleev, Downs cell, Earth, Effective nuclear charge, Effervescence, Einsteinium, Electric charge, Electric potential, Electrical conductor, Electrical resistivity and conductivity, Electride, Electrolysis, Electrolyte, Electron, Electron affinity, Electron configuration, Electron density, Electron shell, Electronegativity, Electronvolt, Electrophilic substitution, Electrostatics, Emission spectrum, Endothermic process, Energy level, Enthalpy of atomization, Enthalpy of fusion, Enthalpy of sublimation, Enthalpy of vaporization, Environmental radioactivity, Ether, European Journal of Inorganic Chemistry, Europium, Eutectic system, Even and odd atomic nuclei, Excited state, Exothermic process, Extended periodic table, Fatty acid, Femtometre, Ferrocene, Fertilizer, Fire extinguisher, Fireworks, Flame test, Flow tracer, Fluorine, Formation and evolution of the Solar System, Fractional crystallization (chemistry), Fractional distillation, Francium, Fulleride, Fume hood, Functional group, Gallium, Gamma ray, Gas, Georg Ernst Stahl, Germanide, Germanium, Glass, Goiânia, Goiânia accident, Gold, Goldschmidt classification, Graphite, Graphite intercalation compound, Great Salt Lake, Grignard reaction, Group (periodic table), Group 11 element, Group 8 element, Gustav Kirchhoff, Half-life, Halite, Halocarbon, Halogen, Hardness, Heart arrhythmia, Helium, Henri-Louis Duhamel du Monceau, History of Earth, Homology (chemistry), Humphry Davy, Hydration energy, Hydride, Hydrochloric acid, Hydrogen, Hydrogen bond, Hydrogen sulfide, Hydron (chemistry), Hydroxide, Hygroscopy, Hyperkalemia, Hypokalemia, Incompatible element, Indium, Inductive effect, Inert pair effect, Inorganic Chemistry (journal), Intercalation (chemistry), Intermetallic, International Atomic Energy Agency, International Union of Pure and Applied Chemistry, Iodine, Iodine-131, Ion, Ion association, Ion transporter, Ionic bonding, Ionic crystal, Ionic radius, Ionization energies of the elements (data page), Ionization energy, Iridium, Iron, Iron group, Island of stability, Isobar (nuclide), Isomerization, Isopropyl alcohol, Isotope, Isotopes of actinium, Isotopes of barium, Isotopes of caesium, Isotopes of francium, Isotopes of lithium, Isotopes of potassium, Isotopes of rubidium, Isotopes of sodium, Jöns Jacob Berzelius, Jerky, Johan August Arfwedson, Johann Wolfgang Döbereiner, John Newlands (chemist), José Bonifácio de Andrada, Joule per mole, Journal of Chemical Education, Journal of Chemical Physics, Journal of Organometallic Chemistry, Journal of the American Chemical Society, Julius Lothar Meyer, Jupiter, Kerosene, Ketone, Krypton, Lanthanide, Latin, Lattice energy, Lead, Lepidolite, Lethal injection, Leucite, Lewis acids and bases, Linus Pauling, Liquid, Lithium, Lithium bromide, Lithium carbonate, Lithium chloride, Lithium cyanide, Lithium fluoride, Lithium hydride, Lithium hydroxide, Lithium iodide, Lithium nitride, Lithium oxide, Lithium perchlorate, Lithium stearate, Lithium-ion battery, Long-lived fission product, Magnesium, Magnesium fluoride, Main-group element, Marguerite Perey, Mass number, McGraw-Hill Encyclopedia of Science & Technology, Median lethal dose, Melting point, Membrane potential, Mendeleev's predicted elements, Mercury (element), Metabolism, Metal ions in aqueous solution, Metallic bonding, Metallic hydrogen, Metallocene, Metastability, Methyl group, Methyllithium, Mineral (nutrient), Mineral oil, Mineral spring, Mineral water, Molar concentration, Mole (unit), Molecule, Monoisotopic element, Monthly Notices of the Royal Astronomical Society, Mood stabilizer, N-Butyllithium, Nanometre, National Academies of Sciences, Engineering, and Medicine, National Academy of Medicine, National Institute of Standards and Technology, Nature (journal), Nature Publishing Group, Neon, Neptune, Neurotransmission, Neutron, Neutron number, Nickel, Nickel tetracarbonyl, Nickeline, Niobium, Nitratine, Nitride, Nitrogen, Noble gas, North Carolina State University, Nuclear and radiation accidents and incidents, Nuclear drip line, Nuclear weapons testing, Nucleon, Nuclide, Octahedron, Octave, Oddo–Harkins rule, Ohm, Oligomer, Open University, Optical spectrometer, Oregon State University, Organolithium reagent, Organomercury, Organometallic chemistry, Organosodium chemistry, Oxford English Dictionary, Oxidation state, Oxide, Oxidizing agent, Oxygen, Ozone, Ozonide, Paramagnetism, Parts-per notation, Pascal (unit), Periodic table, Periodic trends, Peroxide, Petalite, PH, Phenols, Phosphonium, Phosphorus, Physical Review Letters, Pickling, Picometre, Planetary differentiation, Plastic, Platinum group, Plumbide, Pnictogen, Poison, Polarizability, Pollucite, Polonide, Polonium, Polyatomic ion, Polyhedral skeletal electron pair theory, Polysulfide, Post-transition metal, Potassium, Potassium chloride, Potassium hydroxide, Potassium nitrate, Potassium permanganate, Potassium peroxide, Potassium superoxide, Potassium tert-butoxide, Pressure, Primordial nuclide, Propene, Pseudohalogen, Psychiatry, Pure and Applied Chemistry, Pyrolysis, Pyrophoricity, Quantum mechanics, Quaternary ammonium cation, Radioactive decay, Radiogenic nuclide, Radionuclide, Radium, Radon, Reactivity (chemistry), Redox, Reducing agent, Reduction potential, Relative atomic mass, Relativistic quantum chemistry, Rhodium, Rhodocene, Robert Bunsen, Roman numerals, Room temperature, Royal Astronomical Society, Royal Society of Chemistry, Rubidium, Salar de Uyuni, Salt, Salt (chemistry), Salt evaporation pond, Salt pan (geology), Saturn, Schlosser's base, Seabed, Seawater, Selenide, Selenium, Semiconductor, Shielding effect, Significant figures, Silicate, Silicide, Silicon, Silicon dioxide, Silver, Single bond, Sodium, Sodium amalgam, Sodium azide, Sodium chloride, Sodium cyclopentadienide, Sodium hydride, Sodium hydroxide, Sodium naphthalenide, Sodium nitride, Sodium oxide, Sodium peroxide, Sodium sulfide, Sodium tetraphenylborate, Sodium-potassium alloy, Sodium-vapor lamp, Solid, Solubility, Solvated electron, Solvent, Spectroscopy, Spent nuclear fuel, Spodumene, Square antiprism, Stable isotope ratio, Standard conditions for temperature and pressure, Standard electrode potential, Standard electrode potential (data page), Standard enthalpy of formation, Stannide, State of matter, Stellar nucleosynthesis, Stereochemistry, Steric effects, Stibine, Stoichiometry, Strontium, Strontium-90, Subatomic particle, Submarine, Suboxide, Sulfate, Sulfide, Sulfur, Sulfuric acid, Supernova, Superoxide, Sylvite, Tanco Mine, Telluride (chemistry), Tellurium, Tetrahedron, Tetrahydrofuran, Thallium, Thallium(I) fluoride, Thallium(I) iodide, Theodore Gray, Thermal conductivity, Thiol, Thorium, Timeline of chemical element discoveries, Tin, Titanium, Tonne, Toxicology and Applied Pharmacology, Trace element, Trace radioisotope, Transactinide element, Transition metal, Triple bond, Triple-alpha process, Tritium, Trivial name, Tungsten, Unbinilium, Uncertainty, Unified atomic mass unit, United States, United States Geological Survey, Ununennium, Uranium, Uranocene, Uranus, Utah, Utö, Sweden, Valence electron, Vapor pressure, Volt, Voltaic pile, Water, Water vapor, Wiley-Blackwell, Wurtz reaction, Xenon, Ytterbium, Zeolite, Zinc, Zinnwaldite, Zintl phase, Zirconium, 12-Crown-4, 15-Crown-5, 18-Crown-6, 18-electron rule, 2-Butene, 2.2.2-Cryptand, 21-Crown-7. 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The abundance of elements in Earth's crust is shown in tabulated form with the estimated crustal abundance for each chemical element shown as either percentage or parts per million (ppm) by mass (10,000 ppm.
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.
Acetylene (systematic name: ethyne) is the chemical compound with the formula C2H2.
Acetylide refers to chemical compounds with the chemical formulas MC≡CH and MC≡CM, where M is a metal.
An acid–base reaction is a chemical reaction that occurs between an acid and a base, which can be used to determine pH.
Actinium is a chemical element with symbol Ac and atomic number 89.
In physiology, an action potential occurs when the membrane potential of a specific axon location rapidly rises and falls: this depolarisation then causes adjacent locations to similarly depolarise.
In chemistry and physics, activation energy is the energy which must be available to a chemical or nuclear system with potential reactants to result in: a chemical reaction, nuclear reaction, or other various other physical phenomena.
Air conditioning (often referred to as AC, A/C, or air con) is the process of removing heat and moisture from the interior of an occupied space, to improve the comfort of occupants.
In chemistry, an alcohol is any organic compound in which the hydroxyl functional group (–OH) is bound to a carbon.
An aldehyde or alkanal is an organic compound containing a functional group with the structure −CHO, consisting of a carbonyl center (a carbon double-bonded to oxygen) with the carbon atom also bonded to hydrogen and to an R group, which is any generic alkyl or side chain.
In chemistry, an alkali (from Arabic: al-qaly “ashes of the saltwort”) is a basic, ionic salt of an alkali metal or alkaline earth metal chemical element.
Alkali metal halides (also known as alkali halides) are the family of inorganic compounds with the chemical formula MX, where M is an alkali metal and X is a halogen.
An alkalide is a chemical compound in which alkali metals are anions (that is, they bear a negative charge).
The alkaline earth metals are six chemical elements in group 2 of the periodic table.
In organic chemistry, an alkene is an unsaturated hydrocarbon that contains at least one carbon–carbon double bond.
An alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom.
In organic chemistry, an alkyne is an unsaturated hydrocarbon containing at least one carbon—carbon triple bond.
Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or 'decays' into an atom with a mass number that is reduced by four and an atomic number that is reduced by two.
An alum is a type of chemical compound, usually a hydrated double sulfate salt of aluminium with the general formula, where X is a monovalent cation such as potassium or ammonium.
Aluminium or aluminum is a chemical element with symbol Al and atomic number 13.
Aluminium hydroxide, Al(OH)3, is found in nature as the mineral gibbsite (also known as hydrargillite) and its three much rarer polymorphs: bayerite, doyleite, and nordstrandite.
The American Chemical Society (ACS) is a scientific society based in the United States that supports scientific inquiry in the field of chemistry.
An amide (or or), also known as an acid amide, is a compound with the functional group RnE(O)xNR′2 (R and R′ refer to H or organic groups).
Ammonia is a compound of nitrogen and hydrogen with the formula NH3.
The ammonium cation is a positively charged polyatomic ion with the chemical formula.
Amphibole is an important group of generally dark-colored, inosilicate minerals, forming prism or needlelike crystals, composed of double chain tetrahedra, linked at the vertices and generally containing ions of iron and/or magnesium in their structures.
The Ancient Greek language includes the forms of Greek used in ancient Greece and the ancient world from around the 9th century BC to the 6th century AD.
Angewandte Chemie (meaning "Applied Chemistry") is a weekly peer-reviewed scientific journal that is published by Wiley-VCH on behalf of the German Chemical Society (Gesellschaft Deutscher Chemiker).
A substance is anhydrous if it contains no water.
Annalen der Physik (English: Annals of Physics) is one of the oldest scientific journals on physics and has been published since 1799.
Antimonides (sometimes called stibnides) are compounds of antimony with more electropositive elements.
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.
An aqueous solution is a solution in which the solvent is water.
Argon is a chemical element with symbol Ar and atomic number 18.
Argonne National Laboratory is a science and engineering research national laboratory operated by the University of Chicago Argonne LLC for the United States Department of Energy located near Lemont, Illinois, outside Chicago.
Arsenic is a chemical element with symbol As and atomic number 33.
The arsonium cation is a positively charged polyatomic ion with the chemical formula.
Astatine is a radioactive chemical element with symbol At and atomic number 85.
An asterisk (*); from Late Latin asteriscus, from Ancient Greek ἀστερίσκος, asteriskos, "little star") is a typographical symbol or glyph. It is so called because it resembles a conventional image of a star. Computer scientists and mathematicians often vocalize it as star (as, for example, in the A* search algorithm or C*-algebra). In English, an asterisk is usually five-pointed in sans-serif typefaces, six-pointed in serif typefaces, and six- or eight-pointed when handwritten. It is often used to censor offensive words, and on the Internet, to indicate a correction to a previous message. The asterisk is derived from the need of the printers of family trees in feudal times for a symbol to indicate date of birth. The original shape was seven-armed, each arm like a teardrop shooting from the center. In computer science, the asterisk is commonly used as a wildcard character, or to denote pointers, repetition, or multiplication.
An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element.
An atomic clock is a clock device that uses an electron transition frequency in the microwave, optical, or ultraviolet region of the electromagnetic spectrum of atoms as a frequency standard for its timekeeping element.
The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of an atom.
In quantum mechanics, an atomic orbital is a mathematical function that describes the wave-like behavior of either one electron or a pair of electrons in an atom.
The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding cloud of electrons.
Azide is the anion with the formula N. It is the conjugate base of hydrazoic acid (HN3).
Bad Dürkheim is a spa town in the Rhine-Neckar urban agglomeration, and is the seat of the Bad Dürkheim district in Rhineland-Palatinate, Germany.
Barium is a chemical element with symbol Ba and atomic number 56.
A barn (symbol: b) is a unit of area equal to 10−28 m2 (100 fm2).
In chemistry, bases are substances that, in aqueous solution, release hydroxide (OH−) ions, are slippery to the touch, can taste bitter if an alkali, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote certain chemical reactions (base catalysis), accept protons from any proton donor, and/or contain completely or partially displaceable OH− ions.
BASF SE is a German chemical company and the largest chemical producer in the world.
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.
Beta-decay stable isobars are the set of nuclides which cannot undergo beta decay, that is, the transformation of a neutron to a proton or a proton to a neutron within the nucleus.
In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid.
In physical cosmology, Big Bang nucleosynthesis (abbreviated BBN, also known as primordial nucleosynthesis, arch(a)eonucleosynthesis, archonucleosynthesis, protonucleosynthesis and pal(a)eonucleosynthesis) refers to the production of nuclei other than those of the lightest isotope of hydrogen (hydrogen-1, 1H, having a single proton as a nucleus) during the early phases of the Universe.
Bipolar disorder, previously known as manic depression, is a mental disorder that causes periods of depression and periods of abnormally elevated mood.
Bismuth is a chemical element with symbol Bi and atomic number 83.
Bisulfide (systematically named sulfanide and hydrogen(sulfide)(1−)) is an inorganic anion with the chemical formula HS− (also written as SH−).
A block of the periodic table of elements is a set of adjacent groups.
The boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.
A boride is a compound between boron and a less electronegative element, for example silicon boride (SiB3 and SiB6).
Boron is a chemical element with symbol B and atomic number 5.
The boron group are the chemical elements in group 13 of the periodic table, comprising boron (B), aluminium (Al), gallium (Ga), indium (In), thallium (Tl), and perhaps also the chemically uncharacterized nihonium (Nh).
A bracket is a tall punctuation mark typically used in matched pairs within text, to set apart or interject other text.
Brazil (Brasil), officially the Federative Republic of Brazil (República Federativa do Brasil), is the largest country in both South America and Latin America.
A breeder reactor is a nuclear reactor that generates more fissile material than it consumes.
Brine is a high-concentration solution of salt (usually sodium chloride) in water.
Bromine is a chemical element with symbol Br and atomic number 35.
Buckminsterfullerene is a type of fullerene with the formula C60.
Butyllithium may refer to one of 5 isomeric organolithium reagents of which 3 are commonly used in chemical synthesis.
Cadmium is a chemical element with symbol Cd and atomic number 48.
Caesium (British spelling and IUPAC spelling) or cesium (American spelling) is a chemical element with symbol Cs and atomic number 55.
Caesium auride or cesium auride (CsAu) is an ionic compound containing the unusual Au− ion, first discovered in 1978 in the laboratory of Joseph Lagowski.
Caesium chloride or cesium chloride is the inorganic compound with the formula CsCl.
Caesium-137 (Cs-137), cesium-137, or radiocaesium, is a radioactive isotope of caesium which is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nuclear weapons.
Calcium is a chemical element with symbol Ca and atomic number 20.
Calcium chloride is an inorganic compound, a salt with the chemical formula CaCl2.
A carbanion is an anion in which carbon is threevalent (forms three bonds) and bears a formal negative charge in at least one significant mesomeric contributor (resonance form).
Carbon (from carbo "coal") is a chemical element with symbol C and atomic number 6.
Carbon dioxide (chemical formula) is a colorless gas with a density about 60% higher than that of dry air.
The carbon group is a periodic table group consisting of carbon (C), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), and flerovium (Fl).
Carbon monoxide (CO) is a colorless, odorless, and tasteless gas that is slightly less dense than 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.
In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C.
A carboxylic acid is an organic compound that contains a carboxyl group (C(.
Cardiac arrest is a sudden loss of blood flow resulting from the failure of the heart to effectively pump.
Carnallite (also carnalite) is an evaporite mineral, a hydrated potassium magnesium chloride with formula KMgCl3·6(H2O).
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).
A centimetre (international spelling as used by the International Bureau of Weights and Measures; symbol cm) or centimeter (American spelling) is a unit of length in the metric system, equal to one hundredth of a metre, centi being the SI prefix for a factor of.
The central nervous system (CNS) is the part of the nervous system consisting of the brain and spinal cord.
In electromagnetism, charge density is a measure of the amount of electric charge per unit length, surface area, or volume.
Chemical Abstracts Service (CAS) is a division of the American Chemical Society.
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).
In chemistry, polarity is a separation of electric charge leading to a molecule or its chemical groups having an electric dipole or multipole moment.
A chemical property is any of a material's properties that becomes evident during, or after, a chemical reaction; that is, any quality that can be established only by changing a substance's chemical identity.
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.
The Chernobyl disaster, also referred to as the Chernobyl accident, was a catastrophic nuclear accident.
The Chernobyl Nuclear Power Plant Zone of Alienation (translit, translit) is an officially designated exclusion zone around the site of the Chernobyl nuclear reactor disaster.
The Chernobyl Nuclear Power Plant or Chernobyl Nuclear Power Station (Чорнобильська атомна електростанція, Чернобыльская АЭС) is a decommissioned nuclear power station near the city of Pripyat, Ukraine, northwest of the city of Chernobyl, from the Belarus–Ukraine border, and about north of Kiev.
Chlorine is a chemical element with symbol Cl and atomic number 17.
In chemistry, a cluster is an ensemble of bound atoms or molecules that is intermediate in size between a molecule and a bulk solid.
Cobalt is a chemical element with symbol Co and atomic number 27.
Cobaltocene, known also as bis(cyclopentadienyl)cobalt(II) or even "bis Cp cobalt", is an organocobalt compound with the formula Co(C5H5)2.
The Committee on Data for Science and Technology (CODATA) was established in 1966 as an interdisciplinary committee of the International Council for Science.
In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture.
In chemistry, congeners are related chemical substances "related to each other by origin, structure, or function".
Continental or mainland Europe is the continuous continent of Europe excluding its surrounding islands.
A coordinate covalent bond, also known as a dative bond or coordinate bond is a kind of 2-center, 2-electron covalent bond in which the two electrons derive from the same atom.
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.
In chemistry, crystallography, and materials science the coordination number, also called ligancy, of a central atom in a molecule or crystal is the number of atoms, molecules or ions bonded to it.
In coordination chemistry, the coordination sphere refers to a central atom or ion and an array of molecules or anions, the ligands, around.
Copper is a chemical element with symbol Cu (from cuprum) and atomic number 29.
Coulomb explosion is a mechanism for coupling electronic excitation energy from intense electromagnetic fields into the atomic motion.
In physics, a coupling constant or gauge coupling parameter is a number that determines the strength of the force exerted in an interaction.
A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms.
When two particles interact, their mutual cross section is the area transverse to their relative motion within which they must meet in order to scatter from each other.
Crown ethers are cyclic chemical compounds that consist of a ring containing several ether groups.
In geology, the crust is the outermost solid shell of a rocky planet, dwarf planet, or natural satellite.
Cryolite (Na3AlF6, sodium hexafluoroaluminate) is an uncommon mineral identified with the once large deposit at Ivigtût on the west coast of Greenland, depleted by 1987.
Cryptands are a family of synthetic bi- and polycyclic multidentate ligands for a variety of cations.
In crystallography, crystal structure is a description of the ordered arrangement of atoms, ions or molecules in a crystalline material.
In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube.
Centre of protontherapy Institut Curie is one of the leading medical, biological and biophysical research centres in the world.
A cyanide is a chemical compound that contains the group C≡N.
1,3,5,7-Cyclooctatetraene (COT) is an unsaturated derivative of cyclooctane, with the formula C8H8.
Cyclopentadiene is an organic compound with the formula C5H6.
The Dead Sea (יָם הַמֶּלַח lit. Sea of Salt; البحر الميت The first article al- is unnecessary and usually not used.) is a salt lake bordered by Jordan to the east and Israel and Palestine to the west.
Decamethylcobaltocene is an organocobalt compound with the formula Co(C5(CH3)5)2, abbreviated CoCp.
In nuclear science, the decay chain refers to a series of radioactive decays of different radioactive decay products as a sequential series of transformations.
In nuclear physics, a decay product (also known as a daughter product, daughter isotope, radio-daughter, or daughter nuclide) is the remaining nuclide left over from radioactive decay.
A dehumidifier is generally an electrical appliance which reduces and maintains the level of humidity in the air, usually for health or comfort reasons, or to eliminate musty odor and to prevent the growth of mildew.
In geometry, a deltahedron (plural deltahedra) is a polyhedron whose faces are all equilateral triangles.
The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume.
A desiccant is a hygroscopic substance that induces or sustains a state of dryness (desiccation) in its vicinity; it is the opposite of a humectant.
A diagonal relationship is said to exist between certain pairs of diagonally adjacent elements in the second and third periods of the periodic table.
The diamond cubic crystal structure is a repeating pattern of 8 atoms that certain materials may adopt as they solidify.
Diatomic molecules are molecules composed of only two atoms, of the same or different chemical elements.
The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the Institute of Medicine (IOM) of the National Academies (United States).
Dilithium, Li2, is a strongly electrophilic, diatomic molecule comprising two lithium atoms covalently bonded together.
Dipotassium cyclooctatetraenide, sometimes abbreviated K2COT, is an organopotassium compound with the formula K2C8H8.
Dissociation in chemistry and biochemistry is a general process in which molecules (or ionic compounds such as salts, or complexes) separate or split into smaller particles such as atoms, ions or radicals, usually in a reversible manner.
Dmitri Ivanovich Mendeleev (a; 8 February 18342 February 1907 O.S. 27 January 183420 January 1907) was a Russian chemist and inventor.
The Downs' process is an electrochemical method for the commercial preparation of metallic sodium, in which molten NaCl is electrolyzed in a special apparatus called the Downs cell.
Earth is the third planet from the Sun and the only astronomical object known to harbor life.
The effective nuclear charge (often symbolized as Z_ or Z^\ast) is the net positive charge experienced by an electron in a polyelectronic atom.
Effervescence is the escape of gas from an aqueous solution and the foaming or fizzing that results from that release.
Einsteinium is a synthetic element with symbol Es and atomic number 99.
Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field.
An electric potential (also called the electric field potential, potential drop or the electrostatic potential) is the amount of work needed to move a unit positive charge from a reference point to a specific point inside the field without producing any acceleration.
In physics and electrical engineering, a conductor is an object or type of material that allows the flow of an electrical current in one or more directions.
Electrical resistivity (also known as resistivity, specific electrical resistance, or volume resistivity) is a fundamental property that quantifies how strongly a given material opposes the flow of electric current.
An electride is a ionic compound in which an electron is the anion.
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.
The electron is a subatomic particle, symbol or, whose electric charge is negative one elementary charge.
In chemistry and atomic physics, the electron affinity (Eea) of an atom or molecule is defined as the amount of energy released or spent when an electron is added to a neutral atom or molecule in the gaseous state to form a negative ion.
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.
Electron density is the measure of the probability of an electron being present at a specific location.
In chemistry and atomic physics, an electron shell, or a principal energy level, may be thought of as an orbit followed by electrons around an atom's nucleus.
Electronegativity, symbol ''χ'', is a chemical property that describes the tendency of an atom to attract a shared pair of electrons (or electron density) towards itself.
In physics, the electronvolt (symbol eV, also written electron-volt and electron volt) is a unit of energy equal to approximately joules (symbol J).
Electrophilic substitution reactions are chemical reactions in which an electrophile displaces a functional group in a compound, which is typically, but not always, a hydrogen atom.
Electrostatics is a branch of physics that studies electric charges at rest.
The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an atom or molecule making a transition from a high energy state to a lower energy state.
The term endothermic process describes the process or reaction in which the system absorbs energy from its surroundings, usually in the form of heat.
A quantum mechanical system or particle that is bound—that is, confined spatially—can only take on certain discrete values of energy.
The enthalpy of atomization (also atomisation in British spelling) is the enthalpy change that accompanies the total separation of all atoms in a chemical substance (either a chemical element or a chemical compound).
The enthalpy of fusion of a substance, also known as (latent) heat of fusion, is the change in its enthalpy resulting from providing energy, typically heat, to a specific quantity of the substance to change its state from a solid to a liquid, at constant pressure.
The enthalpy of sublimation, or heat of sublimation, is the heat required to change one mole of a substance from solid state to gaseous state at a given combination of temperature and pressure, usually standard temperature and pressure (STP).
The enthalpy of vaporization, (symbol ∆Hvap) also known as the (latent) heat of vaporization or heat of evaporation, is the amount of energy (enthalpy) that must be added to a liquid substance, to transform a quantity of that substance into a gas.
Environmental radioactivity is produced by radioactive materials in the human environment.
Ethers are a class of organic compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups.
The European Journal of Inorganic Chemistry is peer-reviewed scientific journal covering inorganic chemistry.
Europium is a chemical element with symbol Eu and atomic number 63.
A eutectic system from the Greek "ευ" (eu.
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.
In quantum mechanics, an excited state of a system (such as an atom, molecule or nucleus) is any quantum state of the system that has a higher energy than the ground state (that is, more energy than the absolute minimum).
In thermodynamics, the term exothermic process (exo-: "outside") describes a process or reaction that releases energy from the system to its surroundings, usually in the form of heat, but also in a form of light (e.g. a spark, flame, or flash), electricity (e.g. a battery), or sound (e.g. explosion heard when burning hydrogen).
An extended periodic table theorizes about elements beyond oganesson (beyond period 7, or row 7).
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with a long aliphatic chain, which is either saturated or unsaturated.
The femtometre (American spelling femtometer, symbol fm derived from the Danish and Norwegian word femten, "fifteen"+Ancient Greek: μέτρον, metrοn, "unit of measurement") is an SI unit of length equal to 10−15 metres, which means a quadrillionth of one.
Ferrocene is an organometallic compound with the formula Fe(C5H5)2.
A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin (other than liming materials) that is applied to soils or to plant tissues to supply one or more plant nutrients essential to the growth of plants.
A fire extinguisher is an active fire protection device used to extinguish or control small fires, often in emergency situations.
Fireworks are a class of low explosive pyrotechnic devices used for aesthetic and entertainment purposes.
A flame test is an analytic procedure used in chemistry to detect the presence of certain elements, primarily metal ions, based on each element's characteristic emission spectrum.
A flow tracer is any fluid property used to track flow.
Fluorine is a chemical element with symbol F and atomic number 9.
The formation and evolution of the Solar System began 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud.
In chemistry, fractional crystallization is a method of refining substances based on differences in solubility.
Fractional distillation is the separation of a mixture into its component parts, or fractions.
Francium is a chemical element with symbol Fr and atomic number 87.
Fullerides are chemical compounds containing fullerene anions.
A fume hood (sometimes called a fume cupboard or fume closet) is a type of local ventilation device that is designed to limit exposure to hazardous or toxic fumes, vapors or dusts.
In organic chemistry, functional groups are specific substituents or moieties within molecules that are responsible for the characteristic chemical reactions of those molecules.
Gallium is a chemical element with symbol Ga and atomic number 31.
A gamma ray or gamma radiation (symbol γ or \gamma), is penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei.
Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma).
Georg Ernst Stahl (22 October 1659 – 24 May 1734) was a German chemist, physician and philosopher.
A germanide is any binary compound of germanium and a more electropositive element.
Germanium is a chemical element with symbol Ge and atomic number 32.
Glass is a non-crystalline amorphous solid that is often transparent and has widespread practical, technological, and decorative usage in, for example, window panes, tableware, and optoelectronics.
Goiânia is the capital and largest city of the Brazilian state of Goiás.
The Goiânia accident was a radioactive contamination accident that occurred on September 13, 1987, at Goiânia, in the Brazilian state of Goiás, after a forgotten radiotherapy source was taken from an abandoned hospital site in the city.
Gold is a chemical element with symbol Au (from aurum) and atomic number 79, making it one of the higher atomic number elements that occur naturally.
The Goldschmidt classification, developed by Victor Goldschmidt (1888-1947), is a geochemical classification which groups the chemical elements within the Earth according to their preferred host phases into lithophile (rock-loving), siderophile (iron-loving), chalcophile (ore-loving or chalcogen-loving), and atmophile (gas-loving) or volatile (the element, or a compound in which it occurs, is liquid or gaseous at ambient surface conditions).
Graphite, archaically referred to as plumbago, is a crystalline allotrope of carbon, a semimetal, a native element mineral, and a form of coal.
Graphite intercalation compounds (GICs) are complex materials having a formula CXm where the ion Xn+ or Xn− is inserted (intercalated) between the oppositely charged carbon layers.
The Great Salt Lake, located in the northern part of the U.S. state of Utah, is the largest salt water lake in the Western Hemisphere, and the eighth-largest terminal lake in the world.
The Grignard reaction (pronounced) is an organometallic chemical reaction in which alkyl, vinyl, or aryl-magnesium halides (Grignard reagents) add to a carbonyl group in an aldehyde or ketone.
In chemistry, a group (also known as a family) is a column of elements in the periodic table of the chemical elements.
Group 11, by modern IUPAC numbering, is a group of chemical elements in the periodic table, consisting of copper (Cu), silver (Ag), and gold (Au).
Group 8 is a group of chemical element in the periodic table.
Gustav Robert Kirchhoff (12 March 1824 – 17 October 1887) was a German physicist who contributed to the fundamental understanding of electrical circuits, spectroscopy, and the emission of black-body radiation by heated objects.
Half-life (symbol t1⁄2) is the time required for a quantity to reduce to half its initial value.
Halite, commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride (NaCl).
Halocarbon compounds are chemicals in which one or more carbon atoms are linked by covalent bonds with one or more halogen atoms (fluorine, chlorine, bromine or iodine –) resulting in the formation of organofluorine compounds, organochlorine compounds, organobromine compounds, and organoiodine compounds.
The halogens are a group in the periodic table consisting of five chemically related elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
Hardness is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion.
Heart arrhythmia (also known as arrhythmia, dysrhythmia, or irregular heartbeat) is a group of conditions in which the heartbeat is irregular, too fast, or too slow.
Helium (from lit) is a chemical element with symbol He and atomic number 2.
Henri-Louis Duhamel du Monceau (20 July 1700, Paris13 August 1782, Paris), was a French physician, naval engineer and botanist.
The history of Earth concerns the development of planet Earth from its formation to the present day.
In chemistry, homology is the appearance of homologues.
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.
Hydration energy (also hydration enthalpy) is the amount of energy released when one mole of ions undergo hydration which is a special case of solvation.
In chemistry, a hydride is the anion of hydrogen, H−, or, more commonly, it is a compound in which one or more hydrogen centres have nucleophilic, reducing, or basic properties.
Hydrochloric acid is a colorless inorganic chemical system with the formula.
Hydrogen is a chemical element with symbol H and atomic number 1.
A hydrogen bond is a partially electrostatic attraction between a hydrogen (H) which is bound to a more electronegative atom such as nitrogen (N), oxygen (O), or fluorine (F), and another adjacent atom bearing a lone pair of electrons.
Hydrogen sulfide is the chemical compound with the chemical formula H2S.
In chemistry, a hydron is the general name for a cationic form of atomic hydrogen, represented with the symbol.
Hydroxide is a diatomic anion with chemical formula OH−.
Hygroscopy is the phenomenon of attracting and holding water molecules from the surrounding environment, which is usually at normal or room temperature.
Hyperkalemia, also spelled hyperkalaemia, is an elevated level of potassium (K+) in the blood serum.
Hypokalemia, also spelled hypokalaemia, is a low level of potassium (K+) in the blood serum.
In petrology and geochemistry, an incompatible element is one that is unsuitable in size and/or charge to the cation sites of the minerals of which it is included.
Indium is a chemical element with symbol In and atomic number 49.
In chemistry and physics, the inductive effect is an experimentally observed effect of the transmission of charge through a chain of atoms in a molecule, resulting in a permanent dipole in a bond.
The inert pair effect is the tendency of the two electrons in the outermost atomic ''s'' orbital to remain unionized or unshared in compounds of post-transition metals.
Inorganic Chemistry is a biweekly peer-reviewed scientific journal published by the American Chemical Society since 1962.
In chemistry, intercalation is the reversible inclusion or insertion of a molecule (or ion) into materials with layered structures.
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.
The International Atomic Energy Agency (IAEA) is an international organization that seeks to promote the peaceful use of nuclear energy, and to inhibit its use for any military purpose, including nuclear weapons.
The International Union of Pure and Applied Chemistry (IUPAC) is an international federation of National Adhering Organizations that represents chemists in individual countries.
Iodine is a chemical element with symbol I and atomic number 53.
Iodine-131 (131I) is an important radioisotope of iodine discovered by Glenn Seaborg and John Livingood in 1938 at the University of California, Berkeley.
An ion is an atom or molecule that has a non-zero net electrical charge (its total number of electrons is not equal to its total number of protons).
In chemistry, ion association is a chemical reaction whereby ions of opposite electrical charge come together in solution to form a distinct chemical entity.
In biology, an ion transporter (or ion pump) is a transmembrane protein that moves ions across a plasma membrane against their concentration gradient through active transport.
Ionic bonding is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, and is the primary interaction occurring in ionic compounds.
An ionic crystal is a crystal consisting of ions bound together by their electrostatic attraction.
Ionic radius, rion, is the radius of an atom's ion in ionic crystals structure.
The ionization energy (Ei) is qualitatively defined as the amount of energy required to remove the most loosely bound electron, the valence electron, of an isolated gaseous atom to form a cation.
Iridium is a chemical element with symbol Ir and atomic number 77.
Iron is a chemical element with symbol Fe (from ferrum) and atomic number 26.
In chemistry and physics, the iron group refers to elements that are in some way related to iron.
In nuclear physics, the island of stability is the prediction that a set of heavy nuclides with a near magic number of protons and neutrons will temporarily reverse the trend of decreasing stability in elements heavier than uranium.
Isobars are atoms (nuclides) of different chemical elements that have the same number of nucleons.
In chemistry isomerization (also isomerisation) is the process by which one molecule is transformed into another molecule which has exactly the same atoms, but the atoms have a different arrangement e.g. A-B-C → B-A-C (these related molecules are known as isomers). In some molecules and under some conditions, isomerization occurs spontaneously.
Isopropyl alcohol (IUPAC name propan-2-ol; commonly called isopropanol) is a compound with the chemical formula C3H8O.
Isotopes are variants of a particular chemical element which differ in neutron number.
Actinium (89Ac) has no stable isotopes and no characteristic terrestrial isotopic composition, thus a standard atomic weight cannot be given.
Naturally occurring barium (56Ba) is a mix of six stable isotopes and one very long-lived radioactive primordial isotope, barium-130, recently identified as being unstable by geochemical means (from analysis of the presence of its daughter xenon-130 in rocks).
Caesium (55Cs; or cesium) has 40 known isotopes, making it, along with barium and mercury, the element with the most isotopes.
Francium (87Fr) has no stable isotopes.
Naturally occurring lithium (3Li) is composed of two stable isotopes, lithium-6 and lithium-7, with the latter being far more abundant: about 92.5 percent of the atoms.
Potassium (19K) has 24 known isotopes from 32K to 56K.
Rubidium (37Rb) has 32 isotopes, with naturally occurring rubidium being composed of just two isotopes; 85Rb (72.2%) and the radioactive 87Rb (27.8%).
There are twenty recognized isotopes of sodium (11Na), ranging from to and two isomers (and). is the only stable (and the only primordial) isotope.
Baron Jöns Jacob Berzelius (20 August 1779 – 7 August 1848), named by himself and contemporary society as Jacob Berzelius, was a Swedish chemist.
Jerky is lean meat that has been trimmed of fat, cut into strips, and then dried to prevent spoilage.
Johan August Arfwedson (12 January 1792 – 28 October 1841) was a Swedish chemist who discovered the chemical element lithium in 1817 by isolating it as a salt.
Johann Wolfgang Döbereiner (13 December 1780 – 24 March 1849) was a German chemist who is best known for work that foreshadowed the periodic law for the chemical elements and inventing the first lighter, which was known as the Döbereiner's lamp.
John Alexander Reina Newlands (26 November 1837 – 29 July 1898) was a British chemist who did work concerning the periodicity of elements.
José Bonifácio de Andrada e Silva (13 June 17636 April 1838) was a Brazilian statesman, naturalist, professor and poet, born in Santos, São Paulo, then part of the Portuguese Empire.
The joule per mole (symbol: J·mole−1 or J/mol) is an SI derived unit of energy per amount of material.
The Journal of Chemical Education is a monthly peer-reviewed academic journal available in both print and electronic versions.
The Journal of Chemical Physics is a scientific journal published by the American Institute of Physics that carries research papers on chemical physics.
The Journal of Organometallic Chemistry is a peer-reviewed scientific journal published by Elsevier, covering research on organometallic chemistry.
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.
Julius Lothar Meyer (19 August 1830 – 11 April 1895) was a German chemist.
Jupiter is the fifth planet from the Sun and the largest in the Solar System.
Kerosene, also known as paraffin, lamp oil, and coal oil (an obsolete term), is a combustible hydrocarbon liquid which is derived from petroleum.
In chemistry, a ketone (alkanone) is an organic compound with the structure RC(.
Krypton (from translit "the hidden one") is a chemical element with symbol Kr and atomic number 36.
The lanthanide or lanthanoid series of chemical elements comprises the 15 metallic chemical elements with atomic numbers 57 through 71, from lanthanum through lutetium.
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.
Lepidolite is a lilac-gray or rose-colored member of the mica group of minerals with formula K(Li,Al,Rb)2(Al,Si)4O10(F,OH)2.
Lethal injection is the practice of injecting one or more drugs into a person (typically a barbiturate, paralytic, and potassium solution) for the express purpose of causing immediate death.
Leucite is a rock-forming mineral composed of potassium and aluminium tectosilicate K. Crystals have the form of cubic icositetrahedra but, as first observed by Sir David Brewster in 1821, they are not optically isotropic, and are therefore pseudo-cubic.
A Lewis acid is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct.
Linus Carl Pauling (February 28, 1901 – August 19, 1994) was an American chemist, biochemist, peace activist, author, educator, and husband of American human rights activist Ava Helen Pauling.
A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a (nearly) constant volume independent of pressure.
Lithium (from lit) is a chemical element with symbol Li and atomic number 3.
Lithium bromide (LiBr) is a chemical compound of lithium and bromine.
Lithium chloride is a chemical compound with the formula LiCl.
Lithium cyanide is an inorganic compound with the chemical formula LiCN.
Lithium fluoride is an inorganic compound with the chemical formula LiF.
Lithium hydride is an inorganic compound with the formula LiH.
Lithium hydroxide is an inorganic compound with the formula LiOH.
Lithium iodide, or LiI, is a compound of lithium and iodine.
Lithium nitride is a compound with the formula Li3N.
Lithium oxide (2O) or lithia is an inorganic chemical compound.
Lithium perchlorate is the inorganic compound with the formula LiClO4.
Lithium stearate is a chemical compound with the formula LiO2C(CH2)16CH3.
A lithium-ion battery or Li-ion battery (abbreviated as LIB) is a type of rechargeable battery in which lithium ions move from the negative electrode to the positive electrode during discharge and back when charging.
Long-lived fission products (LLFPs) are radioactive materials with a long half-life (more than 200,000 years) produced by nuclear fission of uranium and plutonium.
Magnesium is a chemical element with symbol Mg and atomic number 12.
Magnesium fluoride is an inorganic compound with the formula MgF2.
In chemistry and atomic physics, the main group is the group of elements whose lightest members are represented by helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, and fluorine as arranged in the periodic table of the elements.
Marguerite Catherine Perey (19 October 1909 – 13 May 1975) was a French physicist and a student of Marie Curie.
The mass number (symbol A, from the German word Atomgewichte (atomic weight), also called atomic mass number or nucleon number, is the total number of protons and neutrons (together known as nucleons) in an atomic nucleus. It determines the atomic mass of atoms. Because protons and neutrons both are baryons, the mass number A is identical with the baryon number B as of the nucleus as of the whole atom or ion. The mass number is different for each different isotope of a chemical element. This is not the same as the atomic number (Z) which denotes the number of protons in a nucleus, and thus uniquely identifies an element. Hence, the difference between the mass number and the atomic number gives the number of neutrons (N) in a given nucleus:. The mass number is written either after the element name or as a superscript to the left of an element's symbol. For example, the most common isotope of carbon is carbon-12, or, which has 6 protons and 6 neutrons. The full isotope symbol would also have the atomic number (Z) as a subscript to the left of the element symbol directly below the mass number:. This is technically redundant, as each element is defined by its atomic number, so it is often omitted.
The McGraw-Hill Encyclopedia of Science & Technology is an English-language multivolume encyclopedia, specifically focused on scientific and technical subjects, and published by McGraw-Hill Education.
In toxicology, the median lethal dose, LD50 (abbreviation for "lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a measure of the lethal dose of a toxin, radiation, or pathogen.
The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid at atmospheric pressure.
The term "membrane potential" may refer to one of three kinds of membrane potential.
Dmitri Mendeleev published a periodic table of the chemical elements in 1869 based on properties that appeared with some regularity as he laid out the elements from lightest to heaviest.
Mercury is a chemical element with symbol Hg and atomic number 80.
Metabolism (from μεταβολή metabolē, "change") is the set of life-sustaining chemical transformations within the cells of organisms.
A metal ion in aqueous solution (aqua ion) is a cation, dissolved in water, of chemical formula z+.
Metallic bonding is a type of chemical bonding that arises from the electrostatic attractive force between conduction electrons (in the form of an electron cloud of delocalized electrons) and positively charged metal ions.
Metallic hydrogen is a phase of hydrogen in which it behaves like an electrical conductor.
A metallocene is a compound typically consisting of two cyclopentadienyl anions (abbreviated Cp) bound to a metal center (M) in the oxidation state II, with the resulting general formula (C5H5)2M.
In physics, metastability is a stable state of a dynamical system other than the system's state of least energy.
A methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms — CH3.
Methyllithium is the simplest organolithium reagent with the empirical formula CH3Li.
In the context of nutrition, a mineral is a chemical element required as an essential nutrient by organisms to perform functions necessary for life.
Mineral oil is any of various colorless, odorless, light mixtures of higher alkanes from a mineral source, particularly a distillate of petroleum.
Mineral springs are naturally occurring springs that produce water containing minerals, or other dissolved substances, that alter its taste or give it a purported therapeutic value.
Mineral water is water from a mineral spring that contains various minerals, such as salts and sulfur compounds.
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.
The mole, symbol mol, is the SI unit of amount of substance.
A molecule is an electrically neutral group of two or more atoms held together by chemical bonds.
A monoisotopic element is one of 26 chemical elements which have only a single stable isotope (nuclide).
Monthly Notices of the Royal Astronomical Society (MNRAS) is a peer-reviewed scientific journal covering research in astronomy and astrophysics.
A mood stabilizer is a psychiatric pharmaceutical drug used to treat mood disorders characterized by intense and sustained mood shifts, typically bipolar disorder type I or type II, borderline personality disorder (BPD) and schizophrenia.
n-Butyllithium (abbreviated n-BuLi) is an organolithium reagent.
The nanometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: nm) or nanometer (American spelling) is a unit of length in the metric system, equal to one billionth (short scale) of a metre (m).
The National Academies of Sciences, Engineering, and Medicine (also known as "NASEM" or "the National Academies") is the collective scientific national academy of the United States.
The National Academy of Medicine (NAM), formerly called the Institute of Medicine (IoM), is an American nonprofit, non-governmental organization.
The National Institute of Standards and Technology (NIST) is one of the oldest physical science laboratories in the United States.
Nature is a British multidisciplinary scientific journal, first published on 4 November 1869.
Nature Publishing Group is a division of the international scientific publishing company Springer Nature that publishes academic journals, magazines, online databases, and services in science and medicine.
Neon is a chemical element with symbol Ne and atomic number 10.
Neptune is the eighth and farthest known planet from the Sun in the Solar System.
Neurotransmission (Latin: transmissio "passage, crossing" from transmittere "send, let through"), also called synaptic transmission, is the process by which signaling molecules called neurotransmitters are released by the axon terminal of a neuron (the presynaptic neuron), and bind to and activate the receptors on the dendrites of another neuron (the postsynaptic neuron).
The neutron number, symbol N, is the number of neutrons in a nuclide.
Nickel is a chemical element with symbol Ni and atomic number 28.
Nickel carbonyl (IUPAC name: tetracarbonylnickel) is the organonickel compound with the formula Ni(CO)4.
Nickeline or niccolite is a mineral consisting of nickel arsenide (NiAs) containing 43.9% nickel and 56.1% arsenic.
Niobium, formerly known as columbium, is a chemical element with symbol Nb (formerly Cb) and atomic number 41.
Nitratine or nitratite, also known as cubic niter (UK: nitre), soda niter or Chile saltpeter (UK: Chile saltpetre), is a mineral, the naturally occurring form of sodium nitrate, NaNO3.
In chemistry, a nitride is a compound of nitrogen where nitrogen has a formal oxidation state of 3-.
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.
North Carolina State University (also referred to as NCSU, NC State, or just State) is a public research university located in Raleigh, North Carolina, United States.
A nuclear and radiation accident is defined by the International Atomic Energy Agency (IAEA) as "an event that has led to significant consequences to people, the environment or the facility." Examples include lethal effects to individuals, radioactive isotope to the environment, or reactor core melt." The prime example of a "major nuclear accident" is one in which a reactor core is damaged and significant amounts of radioactive isotopes are released, such as in the Chernobyl disaster in 1986.
The nuclear drip line is the boundary delimiting the zone beyond which atomic nuclei decay by the emission of a proton or neutron.
Nuclear weapons tests are experiments carried out to determine the effectiveness, yield, and explosive capability of nuclear weapons.
In chemistry and physics, a nucleon is either a proton or a neutron, considered in its role as a component of an atomic nucleus.
A nuclide (from nucleus, also known as nuclear species) is an atomic species characterized by the specific constitution of its nucleus, i.e., by its number of protons Z, its number of neutrons N, and its nuclear energy state.
In geometry, an octahedron (plural: octahedra) is a polyhedron with eight faces, twelve edges, and six vertices.
In music, an octave (octavus: eighth) or perfect octave is the interval between one musical pitch and another with half or double its frequency.
The Oddo–Harkins rule holds that an element with an even atomic number (such as carbon: element 6) is more abundant than both elements with the adjacently smaller and larger odd atomic numbers (such as boron: element 5 and nitrogen: element 7, respectively for the carbon).
The ohm (symbol: Ω) is the SI derived unit of electrical resistance, named after German physicist Georg Simon Ohm.
An oligomer (oligo-, "a few" + -mer, "parts") is a molecular complex of chemicals that consists of a few monomer units, in contrast to a polymer, where the number of monomers is, in principle, infinite.
The Open University (OU) is a public distance learning and research university, and one of the biggest universities in the UK for undergraduate education.
An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials.
Oregon State University (OSU) is an international, public research university in the northwest United States, located in Corvallis, Oregon.
Organolithium reagents are organometallic compounds that contain carbon – lithium bonds.
Organomercury refers to the group of organometallic compounds that contain mercury.
Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkaline, alkaline earth, and transition metals, and sometimes broadened to include metalloids like boron, silicon, and tin, as well.
Organosodium chemistry is the chemistry of organometallic compounds containing a carbon to sodium chemical bond.
The Oxford English Dictionary (OED) is the main historical dictionary of the English language, published by the Oxford University Press.
The oxidation state, sometimes referred to as oxidation number, describes degree of oxidation (loss of electrons) of an atom in a chemical compound.
An oxide is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula.
In chemistry, an oxidizing agent (oxidant, oxidizer) is a substance that has the ability to oxidize other substances — in other words to cause them to lose electrons.
Oxygen is a chemical element with symbol O and atomic number 8.
Ozone, or trioxygen, is an inorganic molecule with the chemical formula.
Ozonide is the unstable, reactive polyatomic anion analog of ozone or any of several classes of organic organic peroxide compounds similar formed by the reaction of ozone with an unsaturated compound.
Paramagnetism is a form of magnetism whereby certain materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the applied magnetic field.
In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction.
The pascal (symbol: Pa) is the SI derived unit of pressure used to quantify internal pressure, stress, Young's modulus and ultimate tensile strength.
The periodic table is a tabular arrangement of the chemical elements, ordered by their atomic number, electron configuration, and recurring chemical properties, whose structure shows periodic trends.
Periodic trends are specific patterns that are present in the periodic table that illustrate different aspects of a certain element, including its radius and its electronic properties.
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.
Petalite, also known as castorite, is a lithium aluminium tectosilicate mineral LiAlSi4O10, crystallizing in the monoclinic system.
In chemistry, pH is a logarithmic scale used to specify the acidity or basicity of an aqueous solution.
In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of a hydroxyl group (—OH) bonded directly to an aromatic hydrocarbon group.
The phosphonium (more obscurely: phosphinium) cation describes polyatomic cations with the chemical formula.
Phosphorus is a chemical element with symbol P and atomic number 15.
Physical Review Letters (PRL), established in 1958, is a peer-reviewed, scientific journal that is published 52 times per year by the American Physical Society.
Pickling is the process of preserving or expanding the lifespan of food by either anaerobic fermentation in brine or immersion in vinegar.
The picometre (international spelling as used by the International Bureau of Weights and Measures; SI symbol: pm) or picometer (American spelling) is a unit of length in the metric system, equal to, or one trillionth of a metre, which is the SI base unit of length.
In planetary science, planetary differentiation is the process of separating out different constituents of a planetary body as a consequence of their physical or chemical behaviour, where the body develops into compositionally distinct layers; the denser materials of a planet sink to the center, while less dense materials rise to the surface, generally in a magma ocean.
Plastic is material consisting of any of a wide range of synthetic or semi-synthetic organic compounds that are malleable and so can be molded into solid objects.
The platinum-group metals (abbreviated as the PGMs; alternatively, the platinoids, platinides, platidises, platinum group, platinum metals, platinum family or platinum-group elements (PGEs)) are six noble, precious metallic elements clustered together in the periodic table.
A plumbide can refer to one of two things: an intermetallic compound that contains lead, or a Zintl phase compound with lead as the anion.
A pnictogen is one of the chemical elements in group 15 of the periodic table.
In biology, poisons are substances that cause disturbances in organisms, usually by chemical reaction or other activity on the molecular scale, when an organism absorbs a sufficient quantity.
Polarizability is the ability to form instantaneous dipoles.
Pollucite is a zeolite mineral with the formula (Cs,Na)2Al2Si4O12·2H2O with iron, calcium, rubidium and potassium as common substituting elements.
A polonide is a chemical compound of the radioactive element polonium with any element less electronegative than polonium.
Polonium is a chemical element with symbol Po and atomic number 84.
A polyatomic ion, also known as a molecular ion, is a charged chemical species (ion) composed of two or more atoms covalently bonded or of a metal complex that can be considered to be acting as a single unit.
In chemistry the polyhedral skeletal electron pair theory (PSEPT) provides electron counting rules useful for predicting the structures of clusters such as borane and carborane clusters.
Polysulfides are a class of chemical compounds containing chains of sulfur atoms.
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 chloride (KCl) is a metal halide salt composed of potassium and chlorine.
Potassium hydroxide is an inorganic compound with the formula KOH, and is commonly called caustic potash.
Potassium nitrate is a chemical compound with the chemical formula KNO3.
Potassium permanganate is an inorganic chemical compound and medication.
Potassium peroxide is an inorganic compound with the molecular formula K2O2.
Potassium superoxide is the inorganic compound with the formula.
Potassium tert-butoxide is the chemical compound with the formula K+(CH3)3CO−.
Pressure (symbol: p or P) is the force applied perpendicular to the surface of an object per unit area over which that force is distributed.
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.
Propene, also known as propylene or methyl ethylene, is an unsaturated organic compound having the chemical formula C3H6.
The pseudohalogens are polyatomic analogues of halogens, whose chemistry, resembling that of the true halogens, allows them to substitute for halogens in several classes of chemical compounds.
Psychiatry is the medical specialty devoted to the diagnosis, prevention and treatment of mental disorders.
Pure and Applied Chemistry (abbreviated Pure Appl. Chem.) is the official journal for the International Union of Pure and Applied Chemistry (IUPAC).
Pyrolysis is the thermal decomposition of materials at elevated temperatures in an inert atmosphere.
A pyrophoric substance (from Greek πυροφόρος, pyrophoros, "fire-bearing") ignites spontaneously in air at or below 55 °C (130 °F).
Quantum mechanics (QM; also known as quantum physics, quantum theory, the wave mechanical model, or matrix mechanics), including quantum field theory, is a fundamental theory in physics which describes nature at the smallest scales of energy levels of atoms and subatomic particles.
Quaternary ammonium cations, also known as quats, are positively charged polyatomic ions of the structure, R being an alkyl group or an aryl group.
Radioactive decay (also known as nuclear decay or radioactivity) is the process by which an unstable atomic nucleus loses energy (in terms of mass in its rest frame) by emitting radiation, such as an alpha particle, beta particle with neutrino or only a neutrino in the case of electron capture, gamma ray, or electron in the case of internal conversion.
A radiogenic nuclide is a nuclide that is produced by a process of radioactive decay.
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.
Radon is a chemical element with symbol Rn and atomic number 86.
In chemistry, reactivity is the impetus for which a chemical substance undergoes a chemical reaction, either by itself or with other materials, with an overall release of energy.
Redox (short for reduction–oxidation reaction) (pronunciation: or) is a chemical reaction in which the oxidation states of atoms are changed.
A reducing agent (also called a reductant or reducer) is an element (such as calcium) or compound that loses (or "donates") an electron to another chemical species in a redox chemical reaction.
Reduction potential (also known as redox potential, oxidation / reduction potential, ORP, pE, ε, or E_) is a measure of the tendency of a chemical species to acquire electrons and thereby be reduced.
Relative atomic mass (symbol: A) or atomic weight is a dimensionless physical quantity defined as the ratio of the average mass of atoms of a chemical element in a given sample to one unified atomic mass unit.
Relativistic quantum chemistry combines relativistic mechanics with quantum chemistry to explain elemental properties and structure, especially for the heavier elements of the periodic table.
Rhodium is a chemical element with symbol Rh and atomic number 45.
Rhodocene, formally known as bis(η5-cyclopentadienyl)rhodium(II), is a chemical compound with the formula.
Robert Wilhelm Eberhard Bunsen (30 March 1811N1 – 16 August 1899) was a German chemist.
The numeric system represented by Roman numerals originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages.
Colloquially, room temperature is the range of air temperatures that most people prefer for indoor settings, which feel comfortable when wearing typical indoor clothing.
The Royal Astronomical Society (RAS) is a learned society that began as the Astronomical Society of London in 1820 to support astronomical research (mainly carried on at the time by 'gentleman astronomers' rather than professionals).
The Royal Society of Chemistry (RSC) is a learned society (professional association) in the United Kingdom with the goal of "advancing the chemical sciences".
Rubidium is a chemical element with symbol Rb and atomic number 37.
Salar de Uyuni (or Salar de Tunupa) is the world's largest salt flat at 10 582 square kilometers (4 086 sq mi).
Salt, table salt or common salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in its natural form as a crystalline mineral is known as rock salt or halite.
In chemistry, a salt is an ionic compound that can be formed by the neutralization reaction of an acid and a base.
San Francisco Bay salt ponds salar'' is rich in lithium, and the mine concentrates the brine in the ponds Contemporary solar evaporation salt pans on the island of Lanzarote at Salinas de Janubio Solar evaporation ponds in the Atacama Desert Solar evaporation ponds in the Salt Valley of Añana, Spain Solar evaporation ponds in the Salt Valley of Añana, Spain A salt evaporation pond is a shallow artificial salt pan designed to extract salts from sea water or other brines.
Natural salt pans or salt flats are flat expanses of ground covered with salt and other minerals, usually shining white under the sun.
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter.
Schlosser's base (or Lochmann-Schlosser base) describes various superbasic mixtures of an alkyllithium compound and a potassium alkoxide.
The seabed (also known as the seafloor, sea floor, or ocean floor) is the bottom of the ocean.
Seawater, or salt water, is water from a sea or ocean.
A selenide is a chemical compound containing a selenium anion with oxidation number of −2 (Se2&minus), much as sulfur does in a sulfide.
Selenium is a chemical element with symbol Se and atomic number 34.
A semiconductor material has an electrical conductivity value falling between that of a conductor – such as copper, gold etc.
The shielding effect describes the attraction between an electron and the nucleus in any atom with more than one electron.
The significant figures (also known as the significant digits) of a number are digits that carry meaning contributing to its measurement resolution.
In chemistry, a silicate is any member of a family of anions consisting of silicon and oxygen, usually with the general formula, where 0 ≤ x Silicate anions are often large polymeric molecules with an extense variety of structures, including chains and rings (as in polymeric metasilicate), double chains (as in, and sheets (as in. In geology and astronomy, the term silicate is used to mean silicate minerals, ionic solids with silicate anions; as well as rock types that consist predominantly of such minerals. In that context, the term also includes the non-ionic compound silicon dioxide (silica, quartz), which would correspond to x.
A silicide is a compound that has silicon with (usually) more electropositive elements.
Silicon is a chemical element with symbol Si and atomic number 14.
Silicon dioxide, also known as silica (from the Latin silex), is an oxide of silicon with the chemical formula, most commonly found in nature as quartz and in various living organisms.
Silver is a chemical element with symbol Ag (from the Latin argentum, derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47.
In chemistry, a single bond is a chemical bond between two atoms involving two valence electrons.
Sodium is a chemical element with symbol Na (from Latin natrium) and atomic number 11.
Sodium amalgam, commonly denoted Na(Hg), is an alloy of mercury and sodium.
Sodium azide is the inorganic compound with the formula NaN3.
Sodium chloride, also known as salt, is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions.
Sodium cyclopentadienide is an organosodium compound with the formula C5H5Na.
Sodium hydride is the chemical compound with the empirical formula NaH.
Sodium hydroxide, also known as lye, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations and hydroxide anions. Sodium hydroxide is a highly caustic base and alkali that decomposes proteins at ordinary ambient temperatures and may cause severe chemical burns. It is highly soluble in water, and readily absorbs moisture and carbon dioxide from the air. It forms a series of hydrates NaOH·n. The monohydrate NaOH· crystallizes from water solutions between 12.3 and 61.8 °C. The commercially available "sodium hydroxide" is often this monohydrate, and published data may refer to it instead of the anhydrous compound. As one of the simplest hydroxides, it is frequently utilized alongside neutral water and acidic hydrochloric acid to demonstrate the pH scale to chemistry students. Sodium hydroxide is used in many industries: in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents, and as a drain cleaner. Worldwide production in 2004 was approximately 60 million tonnes, while demand was 51 million tonnes.
Sodium naphthalenide, also known as sodium naphthalide, is an organic salt with the formula Na+C10H8−.
Sodium nitride (Na3N) is the inorganic compound with the formula Na3N.
Sodium oxide is a chemical compound with the formula Na2O.
Sodium peroxide is the inorganic compound with the formula Na2O2.
Sodium sulfide is the chemical compound with the formula Na2S, or more commonly its hydrate Na2S·9H2O.
Sodium tetraphenylborate is the organic compound with the formula NaB(C6H5)4.
Sodium-potassium alloy, colloquially called NaK (commonly pronounced), is an alloy of two alkali metals sodium (Na, atomic number 11) and potassium (K, atomic number 19) and which is usually liquid at room temperature.
A sodium-vapor lamp is a gas-discharge lamp that uses sodium in an excited state to produce light at a characteristic wavelength near 589 nm.
Solid is one of the four fundamental states of matter (the others being liquid, gas, and plasma).
Solubility is the property of a solid, liquid or gaseous chemical substance called solute to dissolve in a solid, liquid or gaseous solvent.
A solvated electron is a free electron in (solvated in) a solution, and is the smallest possible anion.
A solvent (from the Latin solvō, "loosen, untie, solve") is a substance that dissolves a solute (a chemically distinct liquid, solid or gas), resulting in a solution.
Spectroscopy is the study of the interaction between matter and electromagnetic radiation.
Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor (usually at a nuclear power plant).
Spodumene is a pyroxene mineral consisting of lithium aluminium inosilicate, LiAl(SiO3)2, and is a source of lithium.
In geometry, the square antiprism is the second in an infinite set of antiprisms formed by an even-numbered sequence of triangle sides closed by two polygon caps.
The term stable isotope has a meaning similar to stable nuclide, but is preferably used when speaking of nuclides of a specific element.
Standard conditions for temperature and pressure are standard sets of conditions for experimental measurements to be established to allow comparisons to be made between different sets of data.
In electrochemistry, the standard electrode potential is the measure of the individual potential of a reversible electrode at standard state, i.e., with solutes at an effective concentration of 1 mol dm−3 and gases at a pressure of 1 atm.
The data values of standard electrode potentials are given in the table below, in volts relative to the standard hydrogen electrode, and are for the following conditions.
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.
A stannide can refer to an intermetallic compound containing tin combined with one or more other metals; an anion consisting solely of tin atoms or a compound containing such an anion, or, in the field of organometallic chemistry an ionic compound containing an organotin anion (e.g.see an alternative name for such a compound is stannanide.).
In physics, a state of matter is one of the distinct forms in which matter can exist.
Stellar nucleosynthesis is the theory explaining the creation (nucleosynthesis) of chemical elements by nuclear fusion reactions between atoms within the stars.
Stereochemistry, a subdiscipline of chemistry, involves the study of the relative spatial arrangement of atoms that form the structure of molecules and their manipulation.
Steric effects are nonbonding interactions that influence the shape (conformation) and reactivity of ions and molecules.
Stibine is a chemical compound with the formula SbH3.
Stoichiometry is the calculation of reactants and products in chemical reactions.
Strontium is the chemical element with symbol Sr and atomic number 38.
Strontium-90 is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 28.8 years.
In the physical sciences, subatomic particles are particles much smaller than atoms.
A submarine (or simply sub) is a watercraft capable of independent operation underwater.
Suboxides are a class of oxides wherein the electropositive element is in excess relative to the “normal” oxides.
The sulfate or sulphate (see spelling differences) ion is a polyatomic anion with the empirical formula.
Sulfide (systematically named sulfanediide, and sulfide(2−)) (British English sulphide) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions.
Sulfur or sulphur is a chemical element with symbol S and atomic number 16.
Sulfuric acid (alternative spelling sulphuric acid) is a mineral acid with molecular formula H2SO4.
A supernova (plural: supernovae or supernovas, abbreviations: SN and SNe) is a transient astronomical event that occurs during the last stellar evolutionary stages of a star's life, either a massive star or a white dwarf, whose destruction is marked by one final, titanic explosion.
A superoxide is a compound that contains the superoxide anion, which has the chemical formula.
Sylvite, or sylvine, is potassium chloride (KCl) in natural mineral form.
Tanco Mine is an underground caesium and tantalum mine, owned and operated by Cabot Corporation on the north west shore of Bernic Lake, Manitoba, Canada.
The telluride ion is the anion Te2− and its derivatives.
Tellurium is a chemical element with symbol Te and atomic number 52.
In geometry, a tetrahedron (plural: tetrahedra or tetrahedrons), also known as a triangular pyramid, is a polyhedron composed of four triangular faces, six straight edges, and four vertex corners.
Tetrahydrofuran (THF) is an organic compound with the formula (CH2)4O.
Thallium is a chemical element with symbol Tl and atomic number 81.
Thallium(I) fluoride (or thallous fluoride or thallium monofluoride) is the chemical compound composed of thallium and fluorine with the formula TlF.
Thallium(I) iodide is a chemical compound with the formula.
Theodore W. "Theo" Gray is a co-founder of Wolfram Research, science author, and co-founder of app developer Touch Press.
Thermal conductivity (often denoted k, λ, or κ) is the property of a material to conduct heat.
Thiol is an organosulfur compound that contains a carbon-bonded sulfhydryl (R–SH) group (where R represents an alkyl or other organic substituent).
Thorium is a weakly radioactive metallic chemical element with symbol Th and atomic number 90.
The discovery of the 118 chemical elements known to exist today is presented here in chronological order.
Tin is a chemical element with the symbol Sn (from stannum) and atomic number 50.
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;.
Toxicology and Applied Pharmacology is a scientific journal for original research pertaining to action of chemicals, drugs, or natural products to animals or humans.
A trace element is a chemical element whose concentration (or other measure of amount) is very low (a "trace amount").
A trace radioisotope is a radioisotope that occurs naturally in trace amounts (i.e. extremely small).
In chemistry, transactinide elements (also, transactinides, or super-heavy elements) are the chemical elements with atomic numbers from 104 to 120.
In chemistry, the term transition metal (or transition element) has three possible meanings.
A triple bond in chemistry is a chemical bond between two atoms involving six bonding electrons instead of the usual two in a covalent single bond.
The triple-alpha process is a set of nuclear fusion reactions by which three helium-4 nuclei (alpha particles) are transformed into carbon.
Tritium (or; symbol or, also known as hydrogen-3) is a radioactive isotope of hydrogen.
In chemistry, a trivial name is a nonsystematic name for a chemical substance.
Tungsten, or wolfram, is a chemical element with symbol W (referring to wolfram) and atomic number 74.
Unbinilium, also known as eka-radium or simply element 120, is the hypothetical chemical element in the periodic table with symbol Ubn and atomic number 120.
Uncertainty has been called "an unintelligible expression without a straightforward description".
The unified atomic mass unit or dalton (symbol: u, or Da) is a standard unit of mass that quantifies mass on an atomic or molecular scale (atomic mass).
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.
The United States Geological Survey (USGS, formerly simply Geological Survey) is a scientific agency of the United States government.
Ununennium, also known as eka-francium or simply element 119, is the hypothetical chemical element with symbol Uue and atomic number 119.
Uranium is a chemical element with symbol U and atomic number 92.
Uranocene, U(C8H8)2, is an organouranium compound composed of a uranium atom sandwiched between two cyclooctatetraenide rings.
Uranus is the seventh planet from the Sun.
Utah is a state in the western United States.
Utö is a small island in the East of Stockholm archipelago, known for its nature.
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.
Vapor pressure or equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system.
The volt (symbol: V) is the derived unit for electric potential, electric potential difference (voltage), and electromotive force.
The voltaic pile was the first electrical battery that could continuously provide an electric current to a circuit.
Water is a transparent, tasteless, odorless, and nearly colorless chemical substance that is the main constituent of Earth's streams, lakes, and oceans, and the fluids of most living organisms.
Wiley-Blackwell is the international scientific, technical, medical, and scholarly publishing business of John Wiley & Sons.
The Wurtz reaction, named after Charles-Adolphe Wurtz, is a coupling reaction in organic chemistry, organometallic chemistry and recently inorganic main group polymers, whereby two alkyl halides are reacted with sodium metal in dry ether solution to form a higher alkane: Other metals have also been used to effect the Wurtz coupling, among them silver, zinc, iron, activated copper, indium and a mixture of manganese and copper chloride.
Xenon is a chemical element with symbol Xe and atomic number 54.
Ytterbium is a chemical element with symbol Yb and atomic number 70.
Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents and catalysts.
Zinc is a chemical element with symbol Zn and atomic number 30.
Zinnwaldite, KLiFeAl(AlSi3)O10(OH,F)2, potassium lithium iron aluminium silicate hydroxide fluoride is a silicate mineral in the mica group.
In chemistry, a Zintl phase is the product of a reaction between a group 1 (alkali metal) or group 2 (alkaline earth) and any post-transition metal or metalloid (i.e. from group 13, 14, 15 or 16).
Zirconium is a chemical element with symbol Zr and atomic number 40.
12-Crown-4, also called 1,4,7,10-tetraoxacyclododecane and lithium ionophore V, is a crown ether with the formula C8H16O4.
15-Crown-5 is a crown ether with the formula (C2H4O)5.
18-Crown-6 is an organic compound with the formula 6 and the IUPAC name of 1,4,7,10,13,16-hexaoxacyclooctadecane.
The 18-electron rule is a rule used primarily for predicting and rationalizing formulae for stable metal complexes, especially organometallic compounds.
2-Butene is an acyclic alkene with four carbon atoms.
2.2.2-Cryptand is one of the most important members of the cryptand family of chelating agents.
21-Crown-7 is an organic compound with the formula 7 and the IUPAC name of 1,4,7,10,13,16,19-heptaoxacycloheneicosane.
Alkali Metal, Alkali Metals, Alkali group, Alkali metal compound, Alkali metals, Alkaline metal, Group 1 element, Group 1 elements, Hydrogen family, Lithium family, Metals, alkali, Periodic trends in the alkali metals.