CHAPTER 10CHAPTER 10
CONCURRENT ENROLLMENT CONCURRENT ENROLLMENT CHEMISTRYCHEMISTRY
RADIOACTIVE NUCLEIRADIOACTIVE NUCLEINuclei that undergo spontaneous Nuclei that undergo spontaneous
changes and emit energy in the form of changes and emit energy in the form of radiationradiation
Henri Becquerel- 1896Henri Becquerel- 1896 Radioactive decayRadioactive decay A process in which an unstable nucleus A process in which an unstable nucleus
changes energy states and in the changes energy states and in the process emits radiationprocess emits radiation
RADITATIONRADITATION Three types of radiationThree types of radiation
Alpha particles Alpha particles 4422αα or or 44
22He He 2+2+
Identical to the helium nucleus, has two protons and Identical to the helium nucleus, has two protons and two neutronstwo neutrons
Beta particlesBeta particles -1-1
00ββ or or -1-100e-e-
Identical to an electron but is produced when a Identical to an electron but is produced when a nucleus becomes unstable, a neutron changes into a nucleus becomes unstable, a neutron changes into a proton by releasing an electronproton by releasing an electron
Gamma raysGamma rays 00
00γγ A high-energy ray that is like an X ray, but is not a A high-energy ray that is like an X ray, but is not a
particleparticle
Positron and electron capturePositron and electron capture Daughter nucleiDaughter nuclei
radioactive decay The new nuclei produced radioactive decay The new nuclei produced when unstable nuclei undergo when unstable nuclei undergo
PositronPositron Positively charged electron, Positively charged electron, 11
00ee++
This is used in PET scans of the brainThis is used in PET scans of the brain Proton changes into a neutronProton changes into a neutron
Electron captureElectron capture When an electron from outside the nucleus is When an electron from outside the nucleus is
drawn into the nucleus, where it combines drawn into the nucleus, where it combines with a proton to form a neutronwith a proton to form a neutron
ISOTOPE HALF-LIFEISOTOPE HALF-LIFEThe time required for one-half the unstable The time required for one-half the unstable
nuclei in a sample to undergo radioactive nuclei in a sample to undergo radioactive decaydecay
Free radicalFree radicalAn electron-deficient particle that is very An electron-deficient particle that is very
reactivereactiveRadiation sicknessRadiation sickness
The condition associated with and The condition associated with and following short-term exposure to intense following short-term exposure to intense radiationradiation
MEASUREMENTSMEASUREMENTS CurieCurie
Unit of radiation measurement corresponding to 3.7 Unit of radiation measurement corresponding to 3.7 X 10X 101010 nuclear disintegrations per second nuclear disintegrations per second
BecquerelBecquerel Unit of radiation measurement corresponding to one Unit of radiation measurement corresponding to one
nuclear disintegration per secondnuclear disintegration per second RoentgenRoentgen
A biological unit of radiation measurement used with A biological unit of radiation measurement used with X rays and gamma rays; the quantity of radiation that X rays and gamma rays; the quantity of radiation that generates 2.1 X 10generates 2.1 X 1099 ion pairs per 1 cm ion pairs per 1 cm33 of dry air or of dry air or 1.8 X 101.8 X 101212 ion pairs per 1 g of tissue ion pairs per 1 g of tissue
RadRad A biological unit of radiation measurement A biological unit of radiation measurement
corresponding to the transfer of 2.1 X 10corresponding to the transfer of 2.1 X 10-3-3 cal of cal of energy to 1 kg of tissueenergy to 1 kg of tissue
CONTINUEDCONTINUED GrayGray
A biological unit of radiation measurement A biological unit of radiation measurement corresponding to the transfer of 1 J of energy to 1 kg corresponding to the transfer of 1 J of energy to 1 kg of tissueof tissue
RemRem A biological unit of radiation measurement A biological unit of radiation measurement
corresponding to the health effect produced by 1 corresponding to the health effect produced by 1 roentgen of gamma or X-ray regardless of the type of roentgen of gamma or X-ray regardless of the type of radiation involvedradiation involved
Geiger-Müller tube or counterGeiger-Müller tube or counter A radiation-detection device operating on the A radiation-detection device operating on the
principle that ions form when radiation passes through principle that ions form when radiation passes through a tube filled with low-pressure gasa tube filled with low-pressure gas
MEDICAL USES OR MEDICAL USES OR RADIOISOTOPESRADIOISOTOPES
TracerTracer A radioisotope used medically because its progress through the A radioisotope used medically because its progress through the
body or localization in specific organs can be followed.body or localization in specific organs can be followed. Tracers should have short half-livesTracers should have short half-lives Daughter produced from decaying isotope should be nontoxicDaughter produced from decaying isotope should be nontoxic Radioisotope should have a long enough half-life to be prepared Radioisotope should have a long enough half-life to be prepared
and administeredand administered Radiation given off by the isotope should be penetrating gamma Radiation given off by the isotope should be penetrating gamma
rays, so they can be detected rays, so they can be detected Hot spotHot spot
Tissue in which a radioactive tracer concentratesTissue in which a radioactive tracer concentrates Cold spotCold spot
Tissue form which a radioactive tracer is excluded or rejectedTissue form which a radioactive tracer is excluded or rejected
CONTINUEDCONTINUEDRadioisotopes administered internally for Radioisotopes administered internally for
therapeutic use should ideallytherapeutic use should ideallyEmit less penetrating alpha or beta radiation Emit less penetrating alpha or beta radiation
to restrict the extent of damageto restrict the extent of damageHalf-life should be long enough to allow Half-life should be long enough to allow
sufficient time for the desired therapysufficient time for the desired therapyDecay products should be nontoxic and give Decay products should be nontoxic and give
off little or no radiationoff little or no radiationTarget tissue should concentrate the Target tissue should concentrate the
radioisotope to restrict the radiation damageradioisotope to restrict the radiation damage
NONMEDICAL USESNONMEDICAL USES Radioactive datingRadioactive dating
A process for determining the age of artifacts and A process for determining the age of artifacts and rocks, based on the amount and half-life of rocks, based on the amount and half-life of radioisotopes contained in the objectradioisotopes contained in the object
Nuclear fissionNuclear fission A process in which large nuclei split into smaller, A process in which large nuclei split into smaller,
approximately equal-sized nuclei when bombarded by approximately equal-sized nuclei when bombarded by neutronsneutrons
Chain reactionChain reaction A nuclear reaction in which the products of one A nuclear reaction in which the products of one
reaction cause a repeat of the reaction to take place. reaction cause a repeat of the reaction to take place. In the case of uranium fission, neutrons from fission In the case of uranium fission, neutrons from fission reactions cause other fission reaction to occurreactions cause other fission reaction to occur
CONTINUEDCONTINUED Branching chain reactionBranching chain reaction
A reaction in which the products of one reaction A reaction in which the products of one reaction cause more than one more reaction to occurcause more than one more reaction to occur
Critical reactionCritical reaction A constant-rate chain reactionA constant-rate chain reaction
Supercritical reactionSupercritical reaction A branching chain reactionA branching chain reaction
Critical massCritical mass The minimum amount of fissionable material needed The minimum amount of fissionable material needed
to sustain a critical chain reaction at a constant rateto sustain a critical chain reaction at a constant rate Supercritical massSupercritical mass
The minimum amount of fissionable material that The minimum amount of fissionable material that must be present to cause a branching chain reaction must be present to cause a branching chain reaction to occurto occur
LAST PAGELAST PAGEBreeding reactionsBreeding reactions
A nuclear reaction in which isotopes that will A nuclear reaction in which isotopes that will not undergo spontaneous fission are changed not undergo spontaneous fission are changed into isotopes that willinto isotopes that will
Thermonuclear reactionsThermonuclear reactionsNuclear fusion reactions that require a very Nuclear fusion reactions that require a very
high temperature to start themhigh temperature to start themNuclear fusionNuclear fusion
A process in which small nuclei combine or A process in which small nuclei combine or fuse to form larger nucleifuse to form larger nuclei
