## Vocabulary

### alpha decay

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

### beta decay

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

### 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

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

### gamma decay

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

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

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

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

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

### positron emission

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

treatment of cancer by irradiating tumors to shrink or eliminate them

process by which an unstable nucleus loses energy by emitting radiation

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

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

isotope with an unstable nucleus that experiences radioactive decay