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BJU Chemistry Ch 20

Bob Jones Chemistry - Chapter 20

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.
Created by: heidio



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