Chapter 21: Radioactivity and Nuclear Chemistry

Question 1

alpha decay

Answer 1

The form of radioactive decay that occurs when an unstable nucleus emits a particle composed of two protons and two neutrons.

Question 1

alpha particle

Answer 1

A low-energy particle released during alpha decay; equivalent to a He-4 nucleus.

Question 2

beta decay

Answer 2

The form of radioactive decay that occurs when an unstable nucleus emits an electron.

Question 2

beta particle

Answer 2

A medium-energy particle released during beta decay; equivalent to an electron.

Question 3

biological effectiveness factor (RBE)

Answer 3

A correction factor multiplied by the dose of radiation exposure in rad to obtain the dose in rem.

Question 4

chain reaction

Answer 4

A series of reactions in which previous reactions cause future ones; in a fission bomb, neutrons produced by the fission of one uranium nucleus induce fission in other uranium nuclei.

Question 5

electron capture

Answer 5

The form of radioactive decay that occurs when a nucleus assimilates an electron from an inner orbital.

Question 5

critical mass

Answer 5

The necessary amount of a radioactive isotope required to produce a self-sustaining fission reaction.

Question 5

cyclotron

Answer 5

A particle accelerator in which a charged particle is accelerated in an evacuated ring-shaped tube by an alternating voltage applied to each semicircular half of the ring.

Question 6

film-badge dosimeter

Answer 6

A device for monitoring exposure to radiation consisting of photographic film held in a small case that is pinned to clothing.

Question 7

gamma ray

Answer 7

The form of electromagnetic radiation with the shortest wavelength and highest energy.

Question 8

Geiger-Muller counter

Answer 8

A device used to detect radioactivity that uses argon atoms that become ionized in the presense of energetic particles to produce an electrical signal.

Question 10

ionizing power

Answer 10

The ability of radiation to ionize molecules and atoms.

Question 11

linear accelerator

Answer 11

A particle accelerator in which a charged particle is accelerated in an evacuated tube by a potential difference between the ends of the tube or by alternating charges in sections of the tube.

Question 12

magic numbers

Answer 12

Certain numbers of nucleons (N or Z = 2, 8, 20, 28, 50, 82, and N = 126) that confer unique stability.

Question 13

mass defect

Answer 13

The difference in mass between the nucleus of an atom and the sum of the separated particles that make up that nucleus.

Question 14

nuclear equation

Answer 14

An equation that represents nuclear processes such as radioactivity.

Question 14

nuclear binding energy

Answer 14

The amount of energy required to break apart the nucleus into its component nucleons.

Question 15

nuclear fission

Answer 15

The splitting of the nucleus of an atom, which results in a tremendous release of energy.

Question 16

nuclear fusion

Answer 16

The combination of two light nuclei to form a heavier one.

Question 17

gamma ray emission

Answer 17

The form of radioactive decay that occurs when an unstable nucleus emits extremely high-frequencey electromagnetic radiation.

Question 18

nucleons

Answer 18

One of the particles that compose the nucleus, which are protons and neutrons.

Question 19

nuclide

Answer 19

A particular isotope of an atom.

Question 21

penetrating power

Answer 21

The ability of radiation to penetrate matter.

Question 22

phosphorescence

Answer 22

The long-lived emission of light that sometimes follows the absorption of light by certain atoms and molecules.

Question 24

positron

Answer 24

The particle released in positron emission; equal in mass to an electron but opposite in charge.

Question 25

positron emission

Answer 25

The form of radioactive decay that occurs when an unstable nucleus emits a positron.

Question 26

positron emission tomography (PET)

Answer 26

A specialized imaging technique that employs positron-emitting nuclides, such as fluorine-18, as a radiotracer.

Question 27

radioactive

Answer 27

Describes the state of unstable atoms that emit subatomic particles or high-energy electromagnetic radiation.

Question 29

radioactivity

Answer 29

The emission of subatomic particles or high-energy electromagnetic radiation by the unstable nuclei of certain atoms.

Question 30

radiocarbon dating

Answer 30

A form of radiometric dating based on the C-14 isotope.

Question 31

radiometric dating

Answer 31

A technique used to estimate the age of rocks, fossils, or artifacts that depends on the presence of radioactive isotopes and the predictable decay of those isotopes over time.

Question 32

radiotracer

Answer 32

A radiactive nuclide attached to a compound or introduced into a mixture in order to track the movement of the compound or mixture within the body.

Question 33

rem

Answer 33

A unit of radiation exposure that stands for roentgen equivalent man, where a roentgen is defined as the amount of radiation that produces 2.58 x 10^-4C of charge per kg of air.

Question 35

scintillation counter

Answer 35

A device for the detection of radiactivity that includes a material that emits ultraviolet or visible light in response to excitation by energetic particles.

Question 36

strong force

Answer 36

Of the four fundamental forces of physics, the one that is the strongest but acts over the shortest distance; the strong force is responsible for holding the protons and neutrons together in the nucleus of an atom.

Question 37

transmutation

Answer 37

The transformation of one element into another as a result of nuclear reactions.