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Chapter 20 Review67 Total Terms

Chapter 20 Key Terms & Vocabulary

Comprehensive index of all scientific terms, definitions, and examples across Chapter 20: Nuclear Chemistry.

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From Section 20.1: Nuclear Structure and Stability
band of stabilityNuclear Structure and Stability
(also, belt of stability, zone of stability, or valley of stability) region of graph of number of protons versus number of neutrons containing stable (nonradioactive) nuclides
From Section 20.1: Nuclear Structure and Stability
binding energy per nucleonNuclear Energy
total binding energy for the nucleus divided by the number of nucleons in the nucleus
From Section 20.1: Nuclear Structure and Stability
electron volt (eV)Nuclear Energy
measurement unit of nuclear binding energies, with 1 eV equaling the amount energy due to the moving an electron across an electric potential difference of 1 volt
From Section 20.1: Nuclear Structure and Stability
magic numberNuclear Structure and Stability
nuclei with specific numbers of nucleons that are within the band of stability
Example: A magic number is a proton or neutron count that fills a nuclear shell and increases stability; it does not guarantee that a nuclide is nonradioactive.
From Section 20.1: Nuclear Structure and Stability
mass defectNuclear Energy
difference between the mass of an atom and the summed mass of its constituent subatomic particles (or the mass “lost” when nucleons are brought together to form a nucleus)
From Section 20.1: Nuclear Structure and Stability
mass-energy equivalence equationNuclear Energy
Albert Einstein’s relationship showing that mass and energy are equivalent
From Section 20.1: Nuclear Structure and Stability
nuclear binding energyNuclear Energy
energy lost when an atom’s nucleons are bound together (or the energy needed to break a nucleus into its constituent protons and neutrons)
From Section 20.1: Nuclear Structure and Stability
nuclear chemistryNuclear Structure and Stability
study of the structure of atomic nuclei and processes that change nuclear structure
From Section 20.1: Nuclear Structure and Stability
nucleonNuclear Structure and Stability
collective term for protons and neutrons in a nucleus
From Section 20.1: Nuclear Structure and Stability
nuclideNuclear Structure and Stability
nucleus of a particular isotope
From Section 20.1: Nuclear Structure and Stability
radioactivityNuclear Structure and Stability
phenomenon exhibited by an unstable nucleon that spontaneously undergoes change into a nucleon that is more stable; an unstable nucleon is said to be radioactive
Example: Source clarification: the changing object is a nuclide (a nucleus), rather than a single nucleon. The source glossary uses nucleon here.
From Section 20.1: Nuclear Structure and Stability
radioisotopeNuclear Structure and Stability
isotope that is unstable and undergoes conversion into a different, more stable isotope
From Section 20.1: Nuclear Structure and Stability
strong nuclear forceNuclear Structure and Stability
force of attraction between nucleons that holds a nucleus together
From Section 20.2: Nuclear Equations
alpha particleNuclear Particles and Reactions
(α or 24He{}_{2}^{4}\text{He} or 24α){}_{2}^{4}\text{α}) high-energy helium nucleus; a helium atom that has lost two electrons and contains two protons and two neutrons
From Section 20.2: Nuclear Equations
beta particleNuclear Particles and Reactions
(β\text{(β} or −1 0e{}_{−1}^{\,0}\text{e} or −1 0β){}_{−1}^{\,0}\text{β}\text{)} high-energy electron
From Section 20.2: Nuclear Equations
gamma rayNuclear Particles and Reactions
(γ or 00γ){}_{0}^{0}\text{γ}\text{)} short wavelength, high-energy electromagnetic radiation that exhibits wave-particle duality
From Section 20.2: Nuclear Equations
nuclear reactionNuclear Particles and Reactions
change to a nucleus resulting in changes in the atomic number, mass number, or energy state
From Section 20.2: Nuclear Equations
positron (⁰₊₁β or ⁰₊₁e)Nuclear Particles and Reactions
antiparticle to the electron; it has identical properties to an electron, except for having the opposite (positive) charge
From Section 20.2: Nuclear Equations
antimatterNuclear Particles and Reactions
particles with the same mass but opposite properties (such as charge) of ordinary particles
From Section 20.3: Radioactive Decay
alpha (α) decayRadioactive Decay
loss of an alpha particle during radioactive decay
From Section 20.3: Radioactive Decay
beta (β) decayRadioactive Decay
breakdown of a neutron into a proton, which remains in the nucleus, and an electron, which is emitted as a beta particle
From Section 20.3: Radioactive Decay
daughter nuclideRadioactive Decay
nuclide produced by the radioactive decay of another nuclide; may be stable or may decay further
From Section 20.3: Radioactive Decay
electron captureRadioactive Decay
combination of a core electron with a proton to yield a neutron within the nucleus
From Section 20.3: Radioactive Decay
gamma (γ) emissionRadioactive Decay
decay of an excited-state nuclide accompanied by emission of a gamma ray
From Section 20.3: Radioactive Decay
half-life (t₁/₂)Radioactive Decay
time required for half of the atoms in a radioactive sample to decay
From Section 20.3: Radioactive Decay
parent nuclideRadioactive Decay
unstable nuclide that changes spontaneously into another (daughter) nuclide
From Section 20.3: Radioactive Decay
positron emissionRadioactive Decay
(also, β⁺ decay) conversion of a proton into a neutron, which remains in the nucleus, and a positron, which is emitted
From Section 20.3: Radioactive Decay
radioactive decayRadioactive Decay
spontaneous decay of an unstable nuclide into another nuclide
From Section 20.3: Radioactive Decay
radioactive decay seriesRadioactive Decay
chains of successive disintegrations (radioactive decays) that ultimately lead to a stable end-product
From Section 20.3: Radioactive Decay
radiocarbon datingRadiometric Dating
highly accurate means of dating objects 30,000–50,000 years old that were derived from once-living matter; achieved by calculating the ratio of  614C:  612C{}_{\,6}^{14}\text{C}\text{:}\,{}_{\,6}^{12}\text{C} in the object vs. the ratio of  614C:  612C{}_{\,6}^{14}\text{C}\text{:}\,{}_{\,6}^{12}\text{C} in the present-day atmosphere
From Section 20.3: Radioactive Decay
radiometric datingRadiometric Dating
use of radioisotopes and their properties to date the formation of objects such as archeological artifacts, formerly living organisms, or geological formations
From Section 20.4: Transmutation and Nuclear Energy
chain reactionFission and Chain Reactions
repeated fission caused when the neutrons released in fission bombard other atoms
From Section 20.4: Transmutation and Nuclear Energy
containment systemNuclear Reactors
(also, shield) a three-part structure of materials that protects the exterior of a nuclear fission reactor and operating personnel from the high temperatures, pressures, and radiation levels inside the reactor
From Section 20.4: Transmutation and Nuclear Energy
control rodNuclear Reactors
material inserted into the fuel assembly that absorbs neutrons and can be raised or lowered to adjust the rate of a fission reaction
From Section 20.4: Transmutation and Nuclear Energy
critical massFission and Chain Reactions
amount of fissionable material that will support a self-sustaining (nuclear fission) chain reaction
From Section 20.4: Transmutation and Nuclear Energy
fissile (or fissionable)Fission and Chain Reactions
when a material is capable of sustaining a nuclear fission reaction
Example: More precisely, fissile material can fission with slow neutrons. Fissionable is broader and includes nuclides that require fast neutrons.
From Section 20.4: Transmutation and Nuclear Energy
fissionFission and Chain Reactions
splitting of a heavier nucleus into two or more lighter nuclei, usually accompanied by the conversion of mass into large amounts of energy
From Section 20.4: Transmutation and Nuclear Energy
fusionFusion
combination of very light nuclei into heavier nuclei, accompanied by the conversion of mass into large amounts of energy
From Section 20.4: Transmutation and Nuclear Energy
fusion reactorFusion
nuclear reactor in which fusion reactions of light nuclei are controlled
From Section 20.4: Transmutation and Nuclear Energy
nuclear fuelNuclear Reactors
fissionable isotope present in sufficient quantities to provide a self-sustaining chain reaction in a nuclear reactor
From Section 20.4: Transmutation and Nuclear Energy
nuclear moderatorNuclear Reactors
substance that slows neutrons to a speed low enough to cause fission
From Section 20.4: Transmutation and Nuclear Energy
nuclear reactorNuclear Reactors
environment that produces energy via nuclear fission in which the chain reaction is controlled and sustained without explosion
From Section 20.4: Transmutation and Nuclear Energy
nuclear transmutationNuclear Transmutation
conversion of one nuclide into another nuclide
From Section 20.4: Transmutation and Nuclear Energy
particle acceleratorNuclear Transmutation
device that uses electric and magnetic fields to increase the kinetic energy of nuclei used in transmutation reactions
From Section 20.4: Transmutation and Nuclear Energy
reactor coolantNuclear Reactors
assembly used to carry the heat produced by fission in a reactor to an external boiler and turbine where it is transformed into electricity
From Section 20.4: Transmutation and Nuclear Energy
subcritical massFission and Chain Reactions
amount of fissionable material that cannot sustain a chain reaction; less than a critical mass
From Section 20.4: Transmutation and Nuclear Energy
supercritical massFission and Chain Reactions
amount of material in which there is an increasing rate of fission
From Section 20.4: Transmutation and Nuclear Energy
transmutation reactionNuclear Transmutation
bombardment of one type of nuclei with other nuclei or neutrons
From Section 20.4: Transmutation and Nuclear Energy
transuranium elementNuclear Transmutation
element with an atomic number greater than 92; these elements do not occur in nature
Example: Most are made artificially, but traces of some transuranium elements occur naturally; the source's statement is a generalization.
From Section 20.5: Uses of Radioisotopes
chemotherapyRadioisotope Applications
similar to internal radiation therapy, but chemical rather than radioactive substances are introduced into the body to kill cancer cells
From Section 20.5: Uses of Radioisotopes
external beam radiation therapyRadioisotope Applications
radiation delivered by a machine outside the body
From Section 20.5: Uses of Radioisotopes
internal radiation therapyRadioisotope Applications
(also, brachytherapy) radiation from a radioactive substance introduced into the body to kill cancer cells
From Section 20.5: Uses of Radioisotopes
radiation therapyRadioisotope Applications
use of high-energy radiation to damage the DNA of cancer cells, which kills them or keeps them from dividing
From Section 20.5: Uses of Radioisotopes
radioactive tracerRadioisotope Applications
(also, radioactive label) radioisotope used to track or follow a substance by monitoring its radioactive emissions
From Section 20.6: Biological Effects of Radiation
becquerel (Bq)Radiation Units and Dose
SI unit for rate of radioactive decay; 1 Bq = 1 disintegration/s
From Section 20.6: Biological Effects of Radiation
curie (Ci)Radiation Units and Dose
larger unit for rate of radioactive decay frequently used in medicine; 1 Ci = 3.7 ×\times 10¹⁰ disintegrations/s
From Section 20.6: Biological Effects of Radiation
Geiger counterRadiation Detection
instrument that detects and measures radiation via the ionization produced in a Geiger-Müller tube
From Section 20.6: Biological Effects of Radiation
gray (Gy)Radiation Units and Dose
SI unit for measuring radiation dose; 1 Gy = 1 J absorbed/kg tissue
From Section 20.6: Biological Effects of Radiation
ionizing radiationRadiation Effects
radiation that can cause a molecule to lose an electron and form an ion
From Section 20.6: Biological Effects of Radiation
millicurie (mCi)Radiation Units and Dose
larger unit for rate of radioactive decay frequently used in medicine; 1 Ci = 3.7 ×\times 10¹⁰ disintegrations/s
Example: Source clarification: 1 mCi = 0.001 Ci = 3.7 × 10⁷ disintegrations/s; the source definition above gives the value for 1 Ci.
From Section 20.6: Biological Effects of Radiation
nonionizing radiationRadiation Effects
radiation that speeds up the movement of atoms and molecules; it is equivalent to heating a sample, but is not energetic enough to cause the ionization of molecules
From Section 20.6: Biological Effects of Radiation
radiation absorbed dose (rad)Radiation Units and Dose
SI unit for measuring radiation dose, frequently used in medical applications; 1 rad = 0.01 Gy
Example: Source clarification: rad is a non-SI absorbed-dose unit. Gray (Gy) is the SI unit; 1 rad = 0.01 Gy.
From Section 20.6: Biological Effects of Radiation
radiation dosimeterRadiation Detection
device that measures ionizing radiation and is used to determine personal radiation exposure
From Section 20.6: Biological Effects of Radiation
relative biological effectiveness (RBE)Radiation Units and Dose
measure of the relative damage done by radiation
From Section 20.6: Biological Effects of Radiation
roentgen equivalent man (rem)Radiation Units and Dose
unit for radiation damage, frequently used in medicine; 100 rem = 1 Sv
From Section 20.6: Biological Effects of Radiation
scintillation counterRadiation Detection
instrument that uses a scintillator—a material that emits light when excited by ionizing radiation—to detect and measure radiation
From Section 20.6: Biological Effects of Radiation
sievert (Sv)Radiation Units and Dose
SI unit measuring tissue damage caused by radiation; takes into account energy and biological effects of radiation
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20.6 Biological Effects of Radiation
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