Chem Honors Chapter 22

Front 1

nucleons

Back 1

protons and nuetrons

Front 2

nuclide

Back 2

an atom- identified by the number of protons and nuetrons in nucleus

Front 3

mass defect

Back 3

The difference between the mass of an atom and the sum of the masses of its protons, neutrons, and electrons

Front 4

nuclear binding energy

Back 4

nrg released when a nucleus is formed from nucleons

Front 5

binding energy per nucleon

Back 5

NBE/Nucleons

Front 6

Band of stability

Back 6

the stable nuclei cluster over a range of neutron-proton ratios

Front 7

nuclear shell model

Back 7

nucleons exist in different energy levels, or shells, in the nucleus

Front 8

magic numbers

Back 8

2,8,20,28,50,82

Front 9

nuclear reaction

Back 9

a reaction that affects the nucleus of the atom

Front 10

transmutation

Back 10

a change in the identity of a nucleus as a result of a change in the number of its protons

Front 11

radioactive decay

Back 11

the spontaneous disintegrationof a nucleus into a slightly lighter and more stable nucleus, accompanied by emission of pasrticles, emr, or both

Front 12

nuclear radiation

Back 12

particles or electromagnetic radiation emmitted from the nucleus during radioactive decay

Front 13

radioactive nuclide

Back 13

an unstable nucleus that undergoes radioactive decay

Front 14

alpha particle

Back 14

2 protons and neutrons embound together and immited from the nucleus during some kinds of radioactive decay

Front 15

beta particle

Back 15

an electron emmited from the nucleus during some kinds of radioactive decay

Front 16

positron

Back 16

a particle that has the same mass as an electron, but has a positive charge, and is emitted from the nucleus during some kinds of radioactive decay

Front 17

electron capture

Back 17

an inner orbital electron is captured by the nucleus of its own atom

Front 18

gamma rays

Back 18

high-energy electromagnetic waves emitted from a nucleus as it changes from an excited state toa ground energy state

Front 19

Half-life

Back 19

time required for half the atoms of a radioactive nuclide to decay

Front 20

decay series

Back 20

a series of radioactive nuclides produced by successive radioactive decay until a stable nuclide is reached.

Front 21

parent nuclide

Back 21

the haviest nuclide of each decay series

Front 22

daughter nuclides

Back 22

nuclides produced by the decay of the parent nuclides

Front 23

artifical transmutations

Back 23

bombardment of stable nuclei with charged and uncharged particles

Front 24

transuranium elements

Back 24

elements with more than 92 protons in nuclei

Front 25

roentgen

Back 25

a unit used to measure radiation, equal to the amount of radiation that produces 2*10^9 ion pairs when it passes through 1 cm^3 of dry air

Front 26

REM

Back 26

roentgen equivalent, man, quantity of ionizing radiation that does as much damage to human tissue as done by 1 roetgen of high-voltage X rays

Front 27

film badges

Back 27

use exposure of film to measure the approximate radiation exposure of people working with radiation

Front 28

geiger müller counters

Back 28

are instruments that detect radiation by counting electric pulses carried by gas ionized by radiation

Front 29

scintillate

Back 29

absorb ionizing radiation and emit visible light

Front 30

scintillation counters

Back 30

instruments tath convert scintillating light into an electric signal for detecting radiation

Front 31

radioactive dating

Back 31

process by which the approximate age of an object is determined based on the amt of certain radioactive nuclides present

Front 32

radioactive tracers

Back 32

radioactive atoms that are incorporated into substances so that movement of the substances can be followed by radiation deterctors

Front 33

nuclear fission

Back 33

a very heavy nucleus splits into more stable nuclei of intermediate mass

Front 34

chain reaction

Back 34

a reaction in which the material that starts the reaction is also one of the products and can start another reaction

Front 35

critical mass

Back 35

min amount of nuclide that provides the number of neutrons needed to sustain a chain reaction

Front 36

nuclear reactors

Back 36

devices that use controlled'fission chain reactions to produce energy or radioactive nuclides

Front 37

nuclear power plants

Back 37

use heat from nuclear reactiors to produce electrical nergy

Front 38

shielding

Back 38

radiation'absorbing material used to decrease radiation exposure from nuclear reactors, especially gama rays

Front 39

control rods

Back 39

neutron'absorbing rods that help control the reaction by limiting the number of free neutrons

Front 40

moderator

Back 40

slow down the fast neutrons produced by fission

Front 41

nuclear fusion

Back 41

light'mass nuclei combine to form a heavier, more stable nucleus