201 relations: Allies of World War II, Alternating Gradient Synchrotron, American Chemical Society, Amino acid, Angular momentum, Angular momentum operator, Antihydrogen, Antimatter, Antineutron, Antiproton, Astronomy & Astrophysics, Atom, Atomic Energy of Canada Limited, Atomic nucleus, Beta decay, Big Bang, Big Bang nucleosynthesis, Binding energy, Biochemistry, Biological half-life, Bohr model, Boson, Break-even, Brookhaven National Laboratory, CANDU reactor, CERN, Charge radius, Charles Janet, Chemical & Engineering News, Chemical compound, Chemical reaction, Chemistry, Cluster decay, Columbia University, Comet Hale–Bopp, Committee on Data for Science and Technology, Commutative property, Cross section (physics), Cryogenics, Cryostat, Deuterated drug, Deuterium NMR, Deutetrabenazine, Di-deuterated linoleic acid ethyl ester, Dirac equation, Dissociation (chemistry), Distillation, Doublet state, Doubly labeled water, Electric charge, ..., Electric dipole moment, Electromagnetism, Elementary charge, Energy, Environmental science, Ernest Rutherford, Eukaryote, Excited state, Expanded access, Fatty acid, Femtometre, Femtosecond, Ferdinand Brickwedde, Friedreich's ataxia, G-factor (physics), Galileo (spacecraft), Gas, Gilbert N. Lewis, Girdler sulfide process, Global meteoric water line, Ground state, Halley's Comet, Hamiltonian (quantum mechanics), Hans von Halban, Harold Urey, Heavy water, Helium-3, Helium-4, Hydrogen, Hydrogen atom, Hydrogen deuteride, Hydrogen isotope biogeochemistry, Hydrology, Infantile neuroaxonal dystrophy, Infrared, Infrared spectroscopy, Instability, International Union of Pure and Applied Chemistry, Isospin, Isotopes of helium, Isotopes of hydrogen, Isotopes of lithium, Ivy Mike, Jupiter, Kinetic isotope effect, Kuiper belt, Lew Kowarski, Linoleic acid, Lipid peroxidation, Liquid hydrogen, Lithium hydride, Litre, Magnetic moment, Mass number, Mass spectrometry, Mean, Metabolic pathway, Metabolism, Meteoric water, Microwave spectroscopy, Multipole expansion, Muon, National Institute of Standards and Technology, Natural abundance, Nature Biotechnology, Nazi Germany, Neutral current, Neutrino, Neutron, Neutron moderator, Neutron scattering, Neutron source, Neutronium, Nobel Prize in Chemistry, Norwegian heavy water sabotage, Nuclear cross section, Nuclear fission, Nuclear force, Nuclear fusion, Nuclear magnetic moment, Nuclear magnetic resonance, Nuclear magnetic resonance spectroscopy, Nuclear reaction, Nuclear reactor, Nuclear shell model, Nuclear weapon, Nucleon, Nuclide, Nutrient, Ocean, Operator (physics), Parity (physics), Pauli exclusion principle, Physical cosmology, Plutonium, Polyunsaturated fatty acid, Positron, Pressurized heavy-water reactor, Prokaryote, Properties of water, Proton, Proton nuclear magnetic resonance, Proton Synchrotron, Proton–proton chain reaction, Pure and Applied Chemistry, Quadrupole, Quantum mechanics, Quantum number, Quantum state, Quantum superposition, Radioactive decay, Raman spectroscopy, Reduced mass, Relative atomic mass, Research reactor, Rosetta (spacecraft), Rydberg constant, Schrödinger equation, Singlet state, Small molecule, Solar System, Soviet Union, Special unitary group, Spin (physics), Spin-½, Spin–orbit interaction, Stable isotope ratio, Standard conditions for temperature and pressure, Star, Statistical significance, Steady State theory, Sudbury Neutrino Observatory, Symbol (chemistry), Thermonuclear fusion, Thermonuclear weapon, Time (magazine), Tokamak, Total angular momentum quantum number, Triple point, Triplet state, Tritium, Universe, Vacuum flask, Vemork, Vienna Standard Mean Ocean Water, Viscosity, Walter Russell, Wave function, Wilkinson Microwave Anisotropy Probe, World War II, 103P/Hartley. Expand index (151 more) » « Shrink index
The Allies of World War II, called the United Nations from the 1 January 1942 declaration, were the countries that together opposed the Axis powers during the Second World War (1939–1945).
The Alternating Gradient Synchrotron (AGS) is a particle accelerator located at the Brookhaven National Laboratory in Long Island, New York, United States.
The American Chemical Society (ACS) is a scientific society based in the United States that supports scientific inquiry in the field of chemistry.
Amino acids are organic compounds containing amine (-NH2) and carboxyl (-COOH) functional groups, along with a side chain (R group) specific to each amino acid.
In physics, angular momentum (rarely, moment of momentum or rotational momentum) is the rotational equivalent of linear momentum.
In quantum mechanics, the angular momentum operator is one of several related operators analogous to classical angular momentum.
Antihydrogen is the antimatter counterpart of hydrogen.
In modern physics, antimatter is defined as a material composed of the antiparticle (or "partners") to the corresponding particles of ordinary matter.
The antineutron is the antiparticle of the neutron with symbol.
The antiproton,, (pronounced p-bar) is the antiparticle of the proton.
Astronomy & Astrophysics is a peer-reviewed scientific journal covering theoretical, observational, and instrumental astronomy and astrophysics.
An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element.
Atomic Energy of Canada Limited (AECL; Énergie atomique du Canada limitée (EACL)) is a Canadian federal Crown corporation and Canada's largest nuclear science and technology laboratory.
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 Geiger–Marsden gold foil experiment.
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.
The Big Bang theory is the prevailing cosmological model for the universe from the earliest known periods through its subsequent large-scale evolution.
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.
Binding energy (also called separation energy) is the minimum energy required to disassemble a system of particles into separate parts.
Biochemistry, sometimes called biological chemistry, is the study of chemical processes within and relating to living organisms.
The biological half-life of a biological substance is the time it takes for half to be removed by biological processes when the rate of removal is roughly exponential.
In atomic physics, the Rutherford–Bohr model or Bohr model or Bohr diagram, introduced by Niels Bohr and Ernest Rutherford in 1913, depicts the atom as a small, positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus—similar to the structure of the Solar System, but with attraction provided by electrostatic forces rather than gravity.
In quantum mechanics, a boson is a particle that follows Bose–Einstein statistics.
Break-even (or break even), often abbreviated as B/E in finance, is the point of balance making neither a profit nor a loss.
Brookhaven National Laboratory (BNL) is a United States Department of Energy national laboratory located in Upton, New York, on Long Island, and was formally established in 1947 at the site of Camp Upton, a former U.S. Army base.
The CANDU, for Canada Deuterium Uranium, is a Canadian pressurized heavy-water reactor design used to generate electric power.
The European Organization for Nuclear Research (Organisation européenne pour la recherche nucléaire), known as CERN (derived from the name Conseil européen pour la recherche nucléaire), is a European research organization that operates the largest particle physics laboratory in the world.
The rms charge radius is a measure of the size of an atomic nucleus, particularly of a proton or a deuteron.
Charles Janet (15 June 1849 – 7 February 1932) was a French engineer, company director, inventor and biologist.
Chemical & Engineering News (C&EN) is a weekly trade magazine published by the American Chemical Society, providing professional and technical information in the fields of chemistry and chemical engineering.
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) composed of atoms from more than one element held together by chemical bonds.
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.
Chemistry is the scientific discipline involved with compounds composed of atoms, i.e. elements, and molecules, i.e. combinations of atoms: their composition, structure, properties, behavior and the changes they undergo during a reaction with other compounds.
Cluster decay, also named heavy particle radioactivity or heavy ion radioactivity, is a type of nuclear decay in which an atomic nucleus emits a small "cluster" of neutrons and protons, more than in an alpha particle, but less than a typical binary fission fragment.
Columbia University (Columbia; officially Columbia University in the City of New York), established in 1754, is a private Ivy League research university in Upper Manhattan, New York City.
Comet Hale–Bopp (formally designated C/1995 O1) is a comet that was perhaps the most widely observed of the 20th century, and one of the brightest seen for many decades.
The Committee on Data for Science and Technology (CODATA) was established in 1966 as an interdisciplinary committee of the International Council for Science.
In mathematics, a binary operation is commutative if changing the order of the operands does not change the result.
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.
In physics, cryogenics is the production and behaviour of materials at very low temperatures.
A cryostat (from cryo meaning cold and stat meaning stable) is a device used to maintain low cryogenic temperatures of samples or devices mounted within the cryostat.
Deuterated drug is a small molecule medicinal product in which one or more of the hydrogen atoms contained in the drug molecule have been replaced by its heavier stable isotope deuterium.
Deuterium NMR is NMR spectroscopy of deuterium (2H or D), an isotope of hydrogen.
Deutetrabenazine (trade name Austedo) is a vesicular monoamine transporter 2 inhibitor which is used for the treatment of chorea associated with Huntington’s disease and tardive dyskinesia.
Di-deuterated ethyl linoleate (also known as RT001; Di-deuterated linoleic acid ethyl ester, 11,11-D2-Ethyl Linoleate, Ethyl 11,11-D2-Linoleate) is an experimental, orally-bioavailable synthetic deuterated polyunsaturated fatty acid (PUFA), an isotopologue of an essential omega-6 PUFA, linoleic acid.
In particle physics, the Dirac equation is a relativistic wave equation derived by British physicist Paul Dirac in 1928.
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.
Distillation is the process of separating the components or substances from a liquid mixture by selective boiling and condensation.
In quantum mechanics, a doublet is a mixed quantum state of a system with a spin of 1/2, such that there are two allowed values of the spin component, −1/2 and +1/2.
Doubly labeled water is water in which both the hydrogen and the oxygen have been partly or completely replaced (i.e. labeled) with an uncommon isotope of these elements for tracing purposes.
Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field.
The electric dipole moment is a measure of the separation of positive and negative electrical charges within a system, that is, a measure of the system's overall polarity.
Electromagnetism is a branch of physics involving the study of the electromagnetic force, a type of physical interaction that occurs between electrically charged particles.
The elementary charge, usually denoted as or sometimes, is the electric charge carried by a single proton, or equivalently, the magnitude of the electric charge carried by a single electron, which has charge.
In physics, energy is the quantitative property that must be transferred to an object in order to perform work on, or to heat, the object.
Environmental science is an interdisciplinary academic field that integrates physical, biological and information sciences (including ecology, biology, physics, chemistry, plant science, zoology, mineralogy, oceanology, limnology, soil science, geology and physical geography (geodesy), and atmospheric science) to the study of the environment, and the solution of environmental problems.
Ernest Rutherford, 1st Baron Rutherford of Nelson, HFRSE LLD (30 August 1871 – 19 October 1937) was a New Zealand-born British physicist who came to be known as the father of nuclear physics.
Eukaryotes are organisms whose cells have a nucleus enclosed within membranes, unlike Prokaryotes (Bacteria and other Archaea).
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).
Expanded access is the use of an unapproved drug or medical device under specials forms of investigational new drug applications (IND) or IDE application for devices, outside of a clinical trial, by people with serious or life-threatening conditions who do not meet the enrollment criteria for the clinical trial in progress.
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.
A femtosecond is the SI unit of time equal to 10−15 or 1/1,000,000,000,000,000 of a second; that is, one quadrillionth, or one millionth of one billionth, of a second.
Ferdinand Graft Brickwedde (26 March 1903 – 29 March 1989), a physicist at the National Bureau of Standards (now the National Institute of Standards and Technology), in 1931 produced the first sample of hydrogen in which the spectrum of its heavy isotope, deuterium, could be observed.
Friedreich's ataxia is an autosomal recessive inherited disease that causes progressive damage to the nervous system.
A g-factor (also called g value or dimensionless magnetic moment) is a dimensionless quantity that characterizes the magnetic moment and gyromagnetic ratio of an atom, a particle or nucleus.
Galileo was an American unmanned spacecraft that studied the planet Jupiter and its moons, as well as several other Solar System bodies.
Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma).
Gilbert Newton Lewis (October 25 (or 23), 1875 – March 23, 1946) was an American physical chemist known for the discovery of the covalent bond and his concept of electron pairs; his Lewis dot structures and other contributions to valence bond theory have shaped modern theories of chemical bonding.
The Girdler sulfide (GS) process, also known as the GeibSpevack (GS) process, is an industrial production method for filtering out of natural water the heavy water (deuterium oxide.
The Global Meteoric Water Line is an equation defined by the geochemist Harmon Craig that states the average relationship between hydrogen and oxygen isotope ratios in natural terrestrial waters, expressed as a worldwide average.
The ground state of a quantum mechanical system is its lowest-energy state; the energy of the ground state is known as the zero-point energy of the system.
Halley's Comet or Comet Halley, officially designated 1P/Halley, is a short-period comet visible from Earth every 74–79 years.
In quantum mechanics, a Hamiltonian is an operator corresponding to the total energy of the system in most of the cases.
Hans Heinrich von Halban (24 January 1908 – 28 November 1964) was a French physicist, of Austrian-Jewish descent.
Harold Clayton Urey (April 29, 1893 – January 5, 1981) was an American physical chemist whose pioneering work on isotopes earned him the Nobel Prize in Chemistry in 1934 for the discovery of deuterium.
Heavy water (deuterium oxide) is a form of water that contains a larger than normal amount of the hydrogen isotope deuterium (or D, also known as heavy hydrogen), rather than the common hydrogen-1 isotope (or H, also called protium) that makes up most of the hydrogen in normal water.
Helium-3 (He-3, also written as 3He, see also helion) is a light, non-radioactive isotope of helium with two protons and one neutron (common helium having two protons and two neutrons).
Helium-4 is a non-radioactive isotope of the element helium.
Hydrogen is a chemical element with symbol H and atomic number 1.
A hydrogen atom is an atom of the chemical element hydrogen.
Hydrogen deuteride is a diatomic molecule substance or compound of the two isotopes of hydrogen: the majority isotope 1H protium and 2H deuterium.
Hydrogen isotope biogeochemistry is the scientific study of biological, geological, and chemical processes in the environment using the distribution and relative abundance of hydrogen isotopes.
Hydrology is the scientific study of the movement, distribution, and quality of water on Earth and other planets, including the water cycle, water resources and environmental watershed sustainability.
Infantile neuroaxonal dystrophy is a rare pervasive developmental disorder that primarily affects the nervous system.
Infrared radiation (IR) is electromagnetic radiation (EMR) with longer wavelengths than those of visible light, and is therefore generally invisible to the human eye (although IR at wavelengths up to 1050 nm from specially pulsed lasers can be seen by humans under certain conditions). It is sometimes called infrared light.
Infrared spectroscopy (IR spectroscopy or vibrational spectroscopy) involves the interaction of infrared radiation with matter.
In numerous fields of study, the component of instability within a system is generally characterized by some of the outputs or internal states growing without bounds.
The International Union of Pure and Applied Chemistry (IUPAC) is an international federation of National Adhering Organizations that represents chemists in individual countries.
In nuclear physics and particle physics, isospin is a quantum number related to the strong interaction.
Although there are nine known isotopes of helium (2He) (standard atomic weight), only helium-3 and helium-4 are stable.
Hydrogen (1H) has three naturally occurring isotopes, sometimes denoted 1H, 2H, and 3H.
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.
Ivy Mike was the codename given to the first test of a full-scale thermonuclear device, in which part of the explosive yield comes from nuclear fusion.
Jupiter is the fifth planet from the Sun and the largest in the Solar System.
The kinetic isotope effect (KIE) is the change in the reaction rate of a chemical reaction when one of the atoms in the reactants is replaced by one of its isotopes.
The Kuiper belt, occasionally called the Edgeworth–Kuiper belt, is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun.
Lew Kowarski (10 February 1907, Saint Petersburg – 30 July 1979, Geneva) was a naturalized French physicist.
Linoleic acid (LA), a carboxylic acid, is a polyunsaturated omega-6 fatty acid, an 18-carbon chain with two double bonds in cis configuration.
Lipid peroxidation is the oxidative degradation of lipids.
Liquid hydrogen (LH2 or LH2) is the liquid state of the element hydrogen.
Lithium hydride is an inorganic compound with the formula LiH.
The litre (SI spelling) or liter (American spelling) (symbols L or l, sometimes abbreviated ltr) is an SI accepted metric system unit of volume equal to 1 cubic decimetre (dm3), 1,000 cubic centimetres (cm3) or 1/1,000 cubic metre. A cubic decimetre (or litre) occupies a volume of 10 cm×10 cm×10 cm (see figure) and is thus equal to one-thousandth of a cubic metre. The original French metric system used the litre as a base unit. The word litre is derived from an older French unit, the litron, whose name came from Greek — where it was a unit of weight, not volume — via Latin, and which equalled approximately 0.831 litres. The litre was also used in several subsequent versions of the metric system and is accepted for use with the SI,, p. 124. ("Days" and "hours" are examples of other non-SI units that SI accepts.) although not an SI unit — the SI unit of volume is the cubic metre (m3). The spelling used by the International Bureau of Weights and Measures is "litre", a spelling which is shared by almost all English-speaking countries. The spelling "liter" is predominantly used in American English. One litre of liquid water has a mass of almost exactly one kilogram, because the kilogram was originally defined in 1795 as the mass of one cubic decimetre of water at the temperature of melting ice. Subsequent redefinitions of the metre and kilogram mean that this relationship is no longer exact.
The magnetic moment is a quantity that represents the magnetic strength and orientation of a magnet or other object that produces a magnetic field.
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.
Mass spectrometry (MS) is an analytical technique that ionizes chemical species and sorts the ions based on their mass-to-charge ratio.
In mathematics, mean has several different definitions depending on the context.
In biochemistry, a metabolic pathway is a linked series of chemical reactions occurring within a cell.
Metabolism (from μεταβολή metabolē, "change") is the set of life-sustaining chemical transformations within the cells of organisms.
Meteoric water is the water derived from precipitation (snow and rain).
Microwave spectroscopy is the spectroscopy method that employs microwaves, i.e. electromagnetic radiation at GHz frequencies, for the study of matter.
A multipole expansion is a mathematical series representing a function that depends on angles—usually the two angles on a sphere.
The muon (from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 e and a spin of 1/2, but with a much greater mass.
The National Institute of Standards and Technology (NIST) is one of the oldest physical science laboratories in the United States.
In physics, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet.
Nature Biotechnology is a peer reviewed scientific journal published monthly by the Nature Publishing Group.
Nazi Germany is the common English name for the period in German history from 1933 to 1945, when Germany was under the dictatorship of Adolf Hitler through the Nazi Party (NSDAP).
Weak neutral current interactions are one of the ways in which subatomic particles can interact by means of the weak force.
A neutrino (denoted by the Greek letter ν) is a fermion (an elementary particle with half-integer spin) that interacts only via the weak subatomic force and gravity.
In nuclear engineering, a neutron moderator is a medium that reduces the speed of fast neutrons, thereby turning them into thermal neutrons capable of sustaining a nuclear chain reaction involving uranium-235 or a similar fissile nuclide.
Neutron scattering, the irregular dispersal of free neutrons by matter, can refer to either the naturally occurring physical process itself or to the man-made experimental techniques that use the natural process for investigating materials.
A neutron source is any device that emits neutrons, irrespective of the mechanism used to produce the neutrons.
Neutronium (sometimes shortened to neutrium, also referred to as neutrite) is a hypothetical substance composed purely of neutrons.
The Nobel Prize in Chemistry (Nobelpriset i kemi) is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry.
The Norwegian heavy water sabotage (Tungtvannsaksjonen, Tungtvassaksjonen) was a series of operations undertaken by Norwegian saboteurs during World War II to prevent the German nuclear weapon project from acquiring heavy water (deuterium oxide), which could have been used by the Germans to produce nuclear weapons.
The nuclear cross section of a nucleus is used to characterize the probability that a nuclear reaction will occur.
In nuclear physics and nuclear chemistry, nuclear fission is either a nuclear reaction or a radioactive decay process in which the nucleus of an atom splits into smaller parts (lighter nuclei).
The nuclear force (or nucleon–nucleon interaction or residual strong force) is a force that acts between the protons and neutrons of atoms.
In nuclear physics, nuclear fusion is a reaction in which two or more atomic nuclei come close enough to form one or more different atomic nuclei and subatomic particles (neutrons or protons).
The nuclear magnetic moment is the magnetic moment of an atomic nucleus and arises from the spin of the protons and neutrons.
Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a magnetic field absorb and re-emit electromagnetic radiation.
Nuclear magnetic resonance spectroscopy, most commonly known as NMR spectroscopy or magnetic resonance spectroscopy (MRS), is a spectroscopic technique to observe local magnetic fields around atomic nuclei.
In nuclear physics and nuclear chemistry, a nuclear reaction is semantically considered to be the process in which two nuclei, or else a nucleus of an atom and a subatomic particle (such as a proton, neutron, or high energy electron) from outside the atom, collide to produce one or more nuclides that are different from the nuclide(s) that began the process.
A nuclear reactor, formerly known as an atomic pile, is a device used to initiate and control a self-sustained nuclear chain reaction.
In nuclear physics and nuclear chemistry, the nuclear shell model is a model of the atomic nucleus which uses the Pauli exclusion principle to describe the structure of the nucleus in terms of energy levels.
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or from a combination of fission and fusion reactions (thermonuclear bomb).
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.
A nutrient is a substance used by an organism to survive, grow, and reproduce.
An ocean (the sea of classical antiquity) is a body of saline water that composes much of a planet's hydrosphere.
In physics, an operator is a function over a space of physical states to another space of physical states.
In quantum mechanics, a parity transformation (also called parity inversion) is the flip in the sign of one spatial coordinate.
The Pauli exclusion principle is the quantum mechanical principle which states that two or more identical fermions (particles with half-integer spin) cannot occupy the same quantum state within a quantum system simultaneously.
Physical cosmology is the study of the largest-scale structures and dynamics of the Universe and is concerned with fundamental questions about its origin, structure, evolution, and ultimate fate.
Plutonium is a radioactive chemical element with symbol Pu and atomic number 94.
Polyunsaturated fatty acids (PUFAs) are fatty acids that contain more than one double bond in their backbone.
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron.
A pressurized heavy-water reactor (PHWR) is a nuclear reactor, commonly using natural uranium as its fuel, that uses heavy water (deuterium oxide D2O) as its coolant and neutron moderator.
A prokaryote is a unicellular organism that lacks a membrane-bound nucleus, mitochondria, or any other membrane-bound organelle.
Water is a polar inorganic compound that is at room temperature a tasteless and odorless liquid, which is nearly colorless apart from an inherent hint of blue. It is by far the most studied chemical compound and is described as the "universal solvent" and the "solvent of life". It is the most abundant substance on Earth and the only common substance to exist as a solid, liquid, and gas on Earth's surface. It is also the third most abundant molecule in the universe. Water molecules form hydrogen bonds with each other and are strongly polar. This polarity allows it to separate ions in salts and strongly bond to other polar substances such as alcohols and acids, thus dissolving them. Its hydrogen bonding causes its many unique properties, such as having a solid form less dense than its liquid form, a relatively high boiling point of 100 °C for its molar mass, and a high heat capacity. Water is amphoteric, meaning that it is both an acid and a base—it produces + and - ions by self-ionization.
Proton nuclear magnetic resonance (proton NMR, hydrogen-1 NMR, or 1H NMR) is the application of nuclear magnetic resonance in NMR spectroscopy with respect to hydrogen-1 nuclei within the molecules of a substance, in order to determine the structure of its molecules.
The Proton Synchrotron (PS) is a particle accelerator at CERN.
The proton–proton chain reaction is one of the two (known) sets of fusion reactions by which stars convert hydrogen to helium.
Pure and Applied Chemistry (abbreviated Pure Appl. Chem.) is the official journal for the International Union of Pure and Applied Chemistry (IUPAC).
A quadrupole or quadrapole is one of a sequence of configurations of things like electric charge or current, or gravitational mass that can exist in ideal form, but it is usually just part of a multipole expansion of a more complex structure reflecting various orders of complexity.
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.
Quantum numbers describe values of conserved quantities in the dynamics of a quantum system.
In quantum physics, quantum state refers to the state of an isolated quantum system.
Quantum superposition is a fundamental principle of quantum mechanics.
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.
Raman spectroscopy (named after Indian physicist Sir C. V. Raman) is a spectroscopic technique used to observe vibrational, rotational, and other low-frequency modes in a system.
In physics, the reduced mass is the "effective" inertial mass appearing in the two-body problem of Newtonian mechanics.
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.
Research reactors are nuclear reactors that serve primarily as a neutron source.
Rosetta was a space probe built by the European Space Agency launched on 2 March 2004.
The Rydberg constant, symbol R∞ for heavy atoms or RH for hydrogen, named after the Swedish physicist Johannes Rydberg, is a physical constant relating to atomic spectra, in the science of spectroscopy.
In quantum mechanics, the Schrödinger equation is a mathematical equation that describes the changes over time of a physical system in which quantum effects, such as wave–particle duality, are significant.
In quantum mechanics, a singlet state usually refers to a system in which all electrons are paired.
Within the fields of molecular biology and pharmacology, a small molecule is a low molecular weight (< 900 daltons) organic compound that may regulate a biological process, with a size on the order of 1 nm.
The Solar SystemCapitalization of the name varies.
The Soviet Union, officially the Union of Soviet Socialist Republics (USSR) was a socialist state in Eurasia that existed from 1922 to 1991.
In mathematics, the special unitary group of degree, denoted, is the Lie group of unitary matrices with determinant 1.
In quantum mechanics and particle physics, spin is an intrinsic form of angular momentum carried by elementary particles, composite particles (hadrons), and atomic nuclei.
In quantum mechanics, spin is an intrinsic property of all elementary particles.
In quantum physics, the spin–orbit interaction (also called spin–orbit effect or spin–orbit coupling) is a relativistic interaction of a particle's spin with its motion inside a potential.
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.
A star is type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity.
In statistical hypothesis testing, a result has statistical significance when it is very unlikely to have occurred given the null hypothesis.
In cosmology, the Steady State theory is an alternative to the Big Bang model of the evolution of our universe.
The Sudbury Neutrino Observatory (SNO) was a neutrino observatory located 2100 m underground in Vale's Creighton Mine in Sudbury, Ontario, Canada.
In relation to the chemical elements, a symbol is a code for a chemical element.
Thermonuclear fusion is a way to achieve nuclear fusion by using extremely high temperatures.
A thermonuclear weapon is a second-generation nuclear weapon design using a secondary nuclear fusion stage consisting of implosion tamper, fusion fuel, and spark plug which is bombarded by the energy released by the detonation of a primary fission bomb within, compressing the fuel material (tritium, deuterium or lithium deuteride) and causing a fusion reaction.
Time is an American weekly news magazine and news website published in New York City.
A tokamak (Токамáк) is a device that uses a powerful magnetic field to confine a hot plasma in the shape of a torus.
In quantum mechanics, the total angular momentum quantum number parameterises the total angular momentum of a given particle, by combining its orbital angular momentum and its intrinsic angular momentum (i.e., its spin).
In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium.
In quantum mechanics, a triplet is a quantum state of a system with a spin of quantum number s.
Tritium (or; symbol or, also known as hydrogen-3) is a radioactive isotope of hydrogen.
The Universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy.
A vacuum flask (also known as a Dewar flask, Dewar bottle or thermos) is an insulating storage vessel that greatly lengthens the time over which its contents remain hotter or cooler than the flask's surroundings.
Vemork is the name of a hydroelectric power plant outside Rjukan in Tinn, Norway.
Vienna Standard Mean Ocean Water (VSMOW) is a water standard defining the isotopic composition of fresh water.
The viscosity of a fluid is the measure of its resistance to gradual deformation by shear stress or tensile stress.
Walter Bowman Russell (May 19, 1871 – May 19, 1963) was an impressionist American painter (of the Boston School), sculptor, natural philosopher, musician, author, and builder.
A wave function in quantum physics is a mathematical description of the quantum state of an isolated quantum system.
The Wilkinson Microwave Anisotropy Probe (WMAP), originally known as the Microwave Anisotropy Probe (MAP), was a spacecraft operating from 2001 to 2010 which measured temperature differences across the sky in the cosmic microwave background (CMB) – the radiant heat remaining from the Big Bang.
World War II (often abbreviated to WWII or WW2), also known as the Second World War, was a global war that lasted from 1939 to 1945, although conflicts reflecting the ideological clash between what would become the Allied and Axis blocs began earlier.
Comet Hartley 2, designated as 103P/Hartley by the Minor Planet Center, is a small periodic comet with an orbital period of 6.46 years.
Antideuterium, Antideuteron, Deterium, Deuterium exchange measurement, Deuterium-2, Deuteron, Deuterons, Deutrium, Deutron, Dideuterium, Diplon, Heavy Hydrogen, Heavy hydrogen, Hydrogen 2, Hydrogen-2, Pycnodeuterium, Ultra-dense Deuterium, Ultra-dense deuterium.