Radioactivity

Vocabulary

alpha decay

radioactive decay that gives off an α\rm\alpha particle

beta decay

radioactive decay that gives off a β\rm\beta particle

daughter nuclide

nucleus in radioactive decay that remains after the emission of radiation

dosimeter

device that uses a metal chip or crystal to absorb radiation and then indicates the total absorbed amount later when subjected to light or heat respectively

electron capture

process by which a nucleus captures a high-energy electron, transforming a proton into a neutron

external radiation therapy

radiation therapy that administers high-energy radiation, such as gamma rays from a 60Co{}^{60}{\rm{Co}} source, directed at the targeted area

gamma decay

radioactive decay that gives off a γ\rm\gamma ray

gamma radiography

process of testing the integrity of pipelines and other infrastructure by placing a high-energy radiation source on one side of a structure and a sensor on the other side to examine the structure for defects

Geiger counter

device that measures ionizing radiation using a tube filled with inert gas and metal electrodes

half-life (t1/2)

time it takes for half the nuclei of a sample of a radioactive element to decay

internal radiation therapy

radiation therapy that administers radiation such as gamma rays or beta particles to the target area of the body through ingestion or implantation at the target site

ionizing radiation

radiation that has sufficient energy to create ions from the atoms or molecules it strikes

nonionizing radiation

radiation that does not have sufficient energy to create ions from the atoms or molecules it strikes

nuclear medicine

branch of medicine that uses radioisotopes for diagnosis and treatment

parent nuclide

nucleus in radioactive decay that exists before the emission of radiation

positron emission

radioactive decay that emits a positron (+10e)\left({}_{+1}^{\,\,\;0}\rm{e}\right) and transforms one proton in the nucleus into a neutron

radiation therapy

treatment of cancer by irradiating tumors to shrink or eliminate them

radioactive decay

process by which an unstable nucleus loses energy by emitting radiation

radioactive tracer

isotope that emits radiation that can be detected to track the movement of the isotope through a system such as a patient's body

radiocarbon dating

process in which the isotope used to determine the age of a sample is carbon-14 (14C{}^{14}\rm{C})

radioisotope

isotope with an unstable nucleus that experiences radioactive decay

radiolabel

isotope that can be added to a molecule to aid in detection of the molecule

radiometric dating

process of using a radioisotope to determine the age of a sample of material

scintillation counter

instrument that uses the photoelectric effect to measure ionizing radiation