Chapter 21 Vocabulary

Question 1

Nuclear Binding Energy

Answer 1

The energy required to separate a nucleus into its individual nucleons

Question 2

Critical Mass

Answer 2

The amount of fissionable material large enough to maintain a chain reaction with a constant rate of fission

Question 3

Subcritical Mass

Answer 3

A sample that is not massive enough to sustain a chain reaction

Question 4

Ionizing radiation

Answer 4

Radiation with enough energy to knock electrons off some atoms of a bombarded substance to produce ions

Question 5

Nuclear transmutation

Answer 5

A nuclear reaction induced by collision between a nucleus and a neutron or another nucleus

Question 6

Becquerel (bq)

Answer 6

The SI unit for expressing activity; defined as 1 nuclear disintegration per second

Question 7

Curie (Ci)

Answer 7

Unit of activity defined as 3.7x10^10 disintegrations per second

Question 8

Radiotracer

Answer 8

A radioisotope that can be used to trace the path of the element

Question 9

Mass defect

Answer 9

The mass difference between a nucleus and it’s constituent nucleons

Question 10

Fission

Answer 10

A nuclear reaction in which a massive nucleus splits into a smaller nuclei with the simultaneous release of energy

Question 11

Fusion

Answer 11

Creation of energy by joining the nuclei of two hydrogen atoms to form helium

Question 12

Chain reaction

Answer 12

A chemical reaction or other process in which the product themselves promote or spread the reaction, which under certain conditions may accelerate dramatically

Question 13

Supercritical mass

Answer 13

A mass in excess of the critical mass

Question 14

Thermonuclear reactions

Answer 14

Another name for fusion reactions; reactions in which two nuclei are joined to form a more massive one

Question 15

Non ionizing radiation

Answer 15

Radiation that does not cause ionization; generally lower energy

Question 16

Free radical

Answer 16

A substance with one or more unpaired electrons

Question 17

Gray (Gy)

Answer 17

The SI unit of absorbed dose

Question 18

Rad

Answer 18

Radiation absorbed dose

Question 19

Rem

Answer 19

A unit of effective absorbed dose of ionizing radiation in human tissue; product of the radiation in rads and RBE of the radiation

Question 20

Nuclear Reaction

Answer 20

A reaction that involves a change in the nucleus of an atom

Question 21

Nucleons

Answer 21

The two types of subatomic particles residing in the nucleus (protons and neutrons)

Question 22

Radionuclides

Answer 22

Nuclides that are radioactive

Question 23

Nuclide

Answer 23

A nucleus containing a specified number of protons and neutrons

Question 24

Radioisotopes

Answer 24

Atom containing radionuclides

Question 25

Alpha particle

Answer 25

Helium-4 nuclei (bare helium nucleus), contain 2 protons and 2 neutrons

Question 26

Beta particle

Answer 26

A high speed electron with a 1- charge this is emitted during radioactive decay by an unstable nucleus

Question 27

Gamma radiation (rays)

Answer 27

Consists of high energy photons, changing neither the atomic number nor the mass number, usually accompanies other radioactive emission

Question 28

Positron

Answer 28

A particle with the mass of an electron but a positive charge

Question 29

Positron emission

Answer 29

A radioactive decay process that involves the emission of a positron from the nucleus

Question 30

Electron capture

Answer 30

Capture by the nucleus of an electron from the electron cloud surrounding the nucleus

Question 31

Radioactive series/nuclear disintegration series

Answer 31

A series of nuclear reactions that begins with an unstable nucleus and terminated with a stable one

Question 32

Magic numbers

Answer 32

Number of protons and neutrons that result in very stable nuclei

Question 33

Particle accelerators

Answer 33

A machine that moves atomic nuclei at higher and higher speeds until they crash into one another, sometimes forming heavier elements

Question 34

Transuranium Elements

Answer 34

Elements with an atomic number greater than 92

Question 35

Half-life

Answer 35

The time acquired for half of any given quantity of a substance to react

Question 36

Activity

Answer 36

The rate at which a sample decays

Question 37

Beta emission

Answer 37

Release of an electron from the nucleus

Question 38

Alpha decay

Answer 38

Radioactive decay by the emission of an alpha particle