Sections

Glossary

Glossary

activity: the rate of decay for radioactive nuclides

alpha decay: type of radioactive decay in which an atomic nucleus emits an alpha-particle

antielectron: another term for positron

antimatter: composed of antiparticles

atomic mass: the total mass of the protons, neutrons, and electrons in a single atom

atomic number: number of protons in a nucleus

barrier penetration: quantum mechanical effect whereby a particle has a nonzero probability to cross through a potential energy barrier despite not having sufficient energy to pass over the barrier; also called quantum mechanical tunneling

becquerel: SI unit for rate of decay of a radioactive material

beta decay: type of radioactive decay in which an atomic nucleus emits a beta-particle

binding energy: the energy needed to separate nucleus into individual protons and neutrons

binding energy per nucleon: the binding energy calculated per nucleon; it reveals the details of the nuclear force—larger the $BE / A,$ the more stable the nucleus

carbon-14 dating: a radioactive dating technique based on the radioactivity of carbon-14

chart of the nuclides: a table comprising stable and unstable nuclei

curie: the activity of 1g of $^{226} Ra,$ equal to $3.70 \times 10^{10} Bq$

daughter: the nucleus obtained when parent nucleus decays and produces another nucleus following the rules and the conservation laws

decay: the process by which an atomic nucleus of an unstable atom loses mass and energy by emitting ionizing particles

decay constant: quantity that is inversely proportional to the half-life and that is used in equation for number of nuclei as a function of time

decay equation: the equation to find out how much of a radioactive material is left after a given period of time

decay series: process whereby subsequent nuclides decay until a stable nuclide is produced

electron capture: the process in which a proton-rich nuclide absorbs an inner atomic electron and simultaneously emits a neutrino

electron capture equation: equation representing the electron capture

electron’s antineutrino: antiparticle of electron’s neutrino

electron’s neutrino: a subatomic elementary particle which has no net electric charge

gamma decay: type of radioactive decay in which an atomic nucleus emits a gamma particle

Geiger tube: a very common radiation detector that usually gives an audio output

half-life: the time in which there is a 50 percent chance that a nucleus will decay

isotopes: nuclei having the same $Z$ and different Ns

magic numbers: a number that indicates a shell structure for the nucleus in which closed shells are more stable

mass number: number of nucleons in a nucleus

neutrino: an electrically neutral, weakly interacting elementary subatomic particle

neutron: a neutral particle that is found in a nucleus

nuclear reaction energy: the energy created in a nuclear reaction

nucleons: the particles found inside nuclei

nucleus: a region consisting of protons and neutrons at the center of an atom

nuclide: a type of atom whose nucleus has specific numbers of protons and neutrons

parent: the original state of nucleus before decay

photomultiplier: a device that converts light into electrical signals

positron: the particle that results from positive beta decay; also known as an antielectron

positron decay: type of beta decay in which a proton is converted to a neutron, releasing a positron and a neutrino

protons: the positively charged nucleons found in a nucleus

quantum mechanical tunneling: quantum mechanical effect whereby a particle has a nonzero probability to cross through a potential energy barrier despite not having sufficient energy to pass over the barrier; also called barrier penetration

radiation detector: a device that is used to detect and track the radiation from a radioactive reaction

radioactive dating: an application of radioactive decay in which the age of a material is determined by the amount of radioactivity of a particular type that occurs

radius of a nucleus: the radius of a nucleus is $r = r_{0} A^{1 / 3}$

rate of decay: the number of radioactive events per unit time

scintillators: a radiation detection method that records light produced when radiation interacts with materials

solid-state radiation detectors: semiconductors fabricated to directly convert incident radiation into electrical current

tunneling: a quantum mechanical process of potential energy barrier penetration