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nucleosynthesis : process of fusion by which all elements on Earth are believed to have been created
https://openstax.org/books/university-physics-volume-3/pages/10-key-terms
nuclide : nucleus
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parent nucleus : original nucleus before decay
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positron : electron with positive charge
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positron emission tomography (PET) : tomography technique that usesβ+β+emitters and detects the two annihilationγγrays, aiding in source localization
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proton-proton chain : combined reactions that fuse hydrogen nuclei to produce He nuclei
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radiation dose unit (rad) : ionizing energy deposited per kilogram of tissue
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radioactive dating : application of radioactive decay in which the age of a material is determined by the amount of radioactivity of a particular type that occurs
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radioactive decay law : describes the exponential decrease of parent nuclei in a radioactive sample
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radioactive tags : special drugs (radiopharmaceuticals) that allow doctors to track movement of other drugs in the body
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radioactivity : spontaneous emission of radiation from nuclei
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radiopharmaceutical : compound used for medical imaging
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radius of a nucleus : radius of a nucleus is defined asr=r0A1/3r=r0A1/3
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relative biological effectiveness (RBE) : number that expresses the relative amount of damage that a fixed amount of ionizing radiation of a given type can inflict on biological tissues
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roentgen equivalent man (rem) : dose unit more closely related to effects in biological tissue
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sievert (Sv) : SI equivalent of the rem
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single-photon-emission computed tomography (SPECT) : tomography performed withγγ-emitting radiopharmaceuticals
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strong nuclear force : force that binds nucleons together in the nucleus
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transuranic element : element that lies beyond uranium in the periodic table
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The atomic nucleus is composed of protons and neutrons.
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The number of protons in the nucleus is given by the atomic number,Z. The number of neutrons in the nucleus is the neutron number,N. The number of nucleons is mass number,A.
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Atomic nuclei with the same atomic number,Z, but different neutron numbers,N, are isotopes of the same element.
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The atomic mass of an element is the weighted average of the masses of its isotopes.
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The mass defect of a nucleus is the difference between the total mass of a nucleus and the sum of the masses of all its constituent nucleons.
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The binding energy (BE) of a nucleus is equal to the amount of energy released in forming the nucleus, or the mass defect multiplied by the speed of light squared.
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A graph of binding energy per nucleon (BEN) versus atomic numberAimplies that nuclei divided or combined release an enormous amount of energy.
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The binding energy of a nucleon in a nucleus is analogous to the ionization energy of an electron in an atom.
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In the decay of a radioactive substance, if the decay constant (λλ) is large, the half-life is small, and vice versa.
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The radioactive decay law,N=N0e−λt,N=N0e−λt,uses the properties of radioactive substances to estimate the age of a substance.
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Radioactive carbon has the same chemistry as stable carbon, so it mixes into the ecosphere and eventually becomes part of every living organism. By comparing the abundance of14C14Cin an artifact with the normal abundance in living tissue, it is possible to determine the artifact’s age.
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The three types of nuclear radiation are alpha (αα) rays, beta (ββ) rays, and gamma (γγ) rays.
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We representααdecay symbolically byZAX→Z−2A−4X+24HeZAX→Z−2A−4X+24He. There are two types ofββdecay: either an electron (β−β−) or a positron (β+β+) is emitted by a nucleus.γγdecay is represented symbolically byZAX*→ZAX+γZAX*→ZAX+γ.
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When a heavy nucleus decays to a lighter one, the lighter daughter nucleus can become the parent nucleus for the next decay, and so on, producing a decay series.
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Nuclear fission is a process in which the sum of the masses of the product nuclei are less than the masses of the reactants.
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Energy changes in a nuclear fission reaction can be understood in terms of the binding energy per nucleon curve.
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The production of new or different isotopes by nuclear transformation is called breeding, and reactors designed for this purpose are called breeder reactors.
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Nuclear fusion is a reaction in which two nuclei are combined to form a larger nucleus; energy is released when light nuclei are fused to form medium-mass nuclei.
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The amount of energy released by a fusion reaction is known as theQvalue.
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Nuclear fusion explains the reaction between deuterium and tritium that produces a fusion (or hydrogen) bomb; fusion also explains the production of energy in the Sun, the process of nucleosynthesis, and the creation of the heavy elements.
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Nuclear technology is used in medicine to locate and study diseased tissue using special drugs called radiopharmaceuticals. Radioactive tags are used to identify cancer cells in the bones, brain tumors, and Alzheimer’s disease, and to monitor the function of body organs, such as blood flow, heart muscle activity, and...
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The biological effects of ionizing radiation are due to two effects it has on cells: interference with cell reproduction and destruction of cell function.
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Common sources of radiation include that emitted by Earth due to the isotopes of uranium, thorium, and potassium; natural radiation from cosmic rays, soils, and building materials, and artificial sources from medical and dental diagnostic tests.
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Biological effects of nuclear radiation are expressed by many different physical quantities and in many different units, including the rad or radiation dose unit.
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p = 0.3 B r p = 0.3 B r
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W 2 = 2 [ E 1 E 2 + ( p 1 c ) ( p 2 c ) ] + ( m 1 c 2 ) 2 + ( m 2 c 2 ) 2 W 2 = 2 [ E 1 E 2 + ( p 1 c ) ( p 2 c ) ] + ( m 1 c 2 ) 2 + ( m 2 c 2 ) 2
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Δ t = h E Δ t = h E
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v = H 0 d v = H 0 d
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d s 2 = c 2 d t 2 − a ( t ) 2 d Σ 2 d s 2 = c 2 d t 2 − a ( t ) 2 d Σ 2
https://openstax.org/books/university-physics-volume-3/pages/11-key-equations
antiparticle : subatomic particle with the same mass and lifetime as its associated particle, but opposite electric charge
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baryon number : baryon number has the valueB=+1B=+1for baryons,–1–1for antibaryons, and 0 for all other particles and is conserved in particle interactions
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baryons : group of three quarks
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Big Bang : rapid expansion of space that marked the beginning of the universe
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boson : particle with integral spin that are symmetric on exchange
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color : property of particles and that plays the same role in strong nuclear interactions as electric charge does in electromagnetic interactions
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cosmic microwave background radiation (CMBR) : thermal radiation produced by the Big Bang event
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cosmology : study of the origin, evolution, and ultimate fate of the universe
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dark energy : form of energy believed to be responsible for the observed acceleration of the universe
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dark matter : matter in the universe that does not interact with other particles but that can be inferred by deflection of distance star light
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electroweak force : unification of electromagnetic force and weak-nuclear force interactions
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exchange symmetry : property of a system of indistinguishable particles that requires the exchange of any two particles to be unobservable
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fermion : particle with half-integral spin that is antisymmetric on exchange
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Feynman diagram : space-time diagram that describes how particles move and interact
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fundamental force : one of four forces that act between bodies of matter: the strong nuclear, electromagnetic, weak nuclear, and gravitational forces
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gluon : particle that that carry the strong nuclear force between quarks within an atomic nucleus
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grand unified theory : theory of particle interactions that unifies the strong nuclear, electromagnetic, and weak nuclear forces
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hadron : a meson or baryon
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Hubble’s constant : constant that relates speed and distance in Hubble’s law
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Hubble’s law : relationship between the speed and distance of stars and galaxies
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lepton : a fermion that participates in the electroweak force
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lepton number : electron-lepton numberLe,Le,the muon-lepton numberLμ,Lμ,and the tau-lepton numberLτLτare conserved separately in every particle interaction
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mesons : a group of two quarks
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nucleosynthesis : creation of heavy elements, occurring during the Big Bang
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particle accelerator : machine designed to accelerate charged particles; this acceleration is usually achieved with strong electric fields, magnetic fields, or both
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particle detector : detector designed to accurately measure the outcome of collisions created by a particle accelerator; particle detectors are hermetic and multipurpose
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positron : antielectron
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quantum chromodynamics (QCD) : theory that describes strong interactions between quarks
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quantum electrodynamics (QED) : theory that describes the interaction of electrons with photons
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quark : a fermion that participates in the electroweak and strong nuclear force
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redshift : lengthening of the wavelength of light (or reddening) due to cosmological expansion
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Standard Model : model of particle interactions that contains the electroweak theory and quantum chromodynamics (QCD)
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strangeness : particle property associated with the presence of a strange quark
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strong nuclear force : relatively strong attractive force that acts over short distances (about10−1510−15m) responsible for binding protons and neutrons together in atomic nuclei
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synchrotron : circular accelerator that uses alternating voltage and increasing magnetic field strengths to accelerate particles to higher and higher energies
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synchrotron radiation : high-energy radiation produced in a synchrotron accelerator by the circular motion of a charged beam
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theory of everything : a theory of particle interactions that unifies all four fundamental forces
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virtual particle : particle that exists for too short of time to be observable
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W and Z boson : particle with a relatively large mass that carries the weak nuclear force between leptons and quarks
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weak nuclear force : relative weak force (about10−610−6the strength of the strong nuclear force) responsible for decays of elementary particles and neutrino interactions
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The four fundamental forces of nature are, in order of strength: strong nuclear, electromagnetic, weak nuclear, and gravitational. Quarks interact via the strong force, but leptons do not. Both quark and leptons interact via the electromagnetic, weak, and gravitational forces.
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Elementary particles are classified into fermions and boson. Fermions have half-integral spin and obey the exclusion principle. Bosons have integral spin and do not obey this principle. Bosons are the force carriers of particle interactions.
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Quarks and leptons belong to particle families composed of three members each. Members of a family share many properties (charge, spin, participation in forces) but not mass.
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All particles have antiparticles. Particles share the same properties as their antimatter particles, but carry opposite charge.
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Elementary particle interactions are governed by particle conservation laws, which can be used to determine what particle reactions and decays are possible (or forbidden).
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The baryon number conservation law and the three lepton number conversation law are valid for all physical processes. However, conservation of strangeness is valid only for strong nuclear interactions and electromagnetic interactions.
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Six known quarks exist: up (u), down (d), charm (c), strange (s), top (t), and bottom (b). These particles are fermions with half-integral spin and fractional charge.
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Baryons consist of three quarks, and mesons consist of a quark-antiquark pair. Due to the strong force, quarks cannot exist in isolation.
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Evidence for quarks is found in scattering experiments.
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Many types of particle accelerators have been developed to study particles and their interactions. These include linear accelerators, cyclotrons, synchrotrons, and colliding beams.
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Colliding beam machines are used to create massive particles that decay quickly to lighter particles.
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Multipurpose detectors are used to design all aspects of high-energy collisions. These include detectors to measure the momentum and energies of charge particles and photons.
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