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BJU Chemistry Ch 20
Bob Jones Chemistry - Chapter 20
Term | Definition |
---|---|
activity | The number of radioactive decays per unit of time as measured by particles or rays produced. |
alpha particle | The nucleus of the helium atom (two protons, two neutrons) produced as the by-product of a nuclear decay process. |
band of stability | The group of stable nuclides represented on a graph of atomic numbers versus number of neutrons. |
becquerel | The SI unit of measure describing the radioactivity of a substance; 1 Bq = 1 disintegration per second. |
beta particle | An electron that has been formed in and emitted from a nucleus during a nuclear decay process. |
chain reaction | A self-sustaining process in which neutrons produced from fission reactions cause more fission reactions. |
critical mass | The smallest mass of a fissionable substance that can sustain a chain reaction. |
daughter nuclide | The product of the radioactive decay of a nuclide. |
electron capture | A process that occurs when a nucleus pulls in one of its closest electrons and combines it with a proton to form a neutron, releasing an x-ray photon in the process. |
fission | The transmutation of a massive nucleus to split into smaller and more stable nuclei, releasing large amounts of energy in the process. |
fusion | The transmutation of two or more smaller nuclei to combine into one larger, more stable nucleus, releasing large amounts of energy in the process. |
gamma ray | An uncharged electromagnetic wave of very high frequency and short wavelength. It is the most harmful type of radiation. |
gray | The SI unit of biological radiation absorption. |
half-life | The amount of time required for half of the atoms of a parent nuclide in a radioactive sample to decay into its daughter nuclide. |
ionizing radiation | Particles and waves that have enough energy to knock electrons out of an atom. |
magic number | The number of nucleons (either protons or neutrons) in a full nuclear shell, according to the nuclear shell model. |
mass defect | The difference between the mass of a nucleus and the sum of the masses of the particles from which the nucleus was formed. |
nuclear binding energy | The energy required to separate all the protons and neutrons in a specific nucleus from each other; the energy equivalent of the nucleus's mass defect. |
nuclear bombardment reaction | A nuclear reaction that is triggered when a nucleus is struck by a high-energy particle or another nucleus. |
nuclear equation | An equation that describes the change that occurs when nuclei decay, split, or fuse to release radiation. |
nuclear radiation | The waves and particles emitted during nuclear decay to make an atom more stable. |
nucleon | A proton or neutron. |
nuclide | A unique atom of an element expressed using isotopic notation. The term is used instead of isotope when discussing the nuclear characteristics of different elements. |
parent nuclide | A nuclide that undergoes radioactive decay to change into a daughter nuclide. |
positron | An electron with a positive charge; an anti-electron. |
positron emission | A nuclear decay in which one of an atom's protons is converted into a neutron and a positron, which is emitted. |
radioactive decay | The change of an unstable parent nuclide to a more stable daughter nuclide. |
radioactive decay series | A series of sequential reactions of alpha and beta emissions that change larger, unstable nuclides to smaller, stable nuclides. |
radioactivity | The spontaneous emission of penetrating rays from nuclei. |
radioisotope | Any radioactive isotope of an element. |
sievert | A unit of measure of the biological effects of different types of radiation on people. |
transmutation | Any process that converts one element into another by changing the number of protons, such as the transmutation of lead into gold. |
transuranium element | An element with an atomic number higher than 92. |