Sections
Key Terms
Key Terms
- activity
- rate of decay for radioactive nuclides
- alpha decay
- type of radioactive decay in which an atomic nucleus emits an alpha particle
- anger camera
- common medical imaging device that uses a scintillator connected to a series of photomultipliers
- atomic number
- number of protons in a nucleus
- 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
- carbon-14 dating
- radioactive dating technique based on the radioactivity of carbon-14
- chain reaction
- self-sustaining sequence of events, exemplified by the self-sustaining nature of a fission reaction at critical mass
- critical mass
- minimum amount necessary for self-sustained fission of a given nuclide
- decay constant
- quantity that is inversely proportional to the half-life and that is used in the equation for number of nuclei as a function of time
- energy-level diagram
- a diagram used to analyze the energy levels of electrons in the orbits of an atom
- excited state
- any state beyond the n = 1 orbital in which the electron stores energy
- Fraunhofer lines
- black lines shown on an absorption spectrum that show the wavelengths absorbed by a gas
- gamma decay
- type of radioactive decay in which an atomic nucleus emits a gamma ray
- Geiger tube
- very common radiation detector that usually gives an audio output
- ground state
- the n=1 orbital of an electron
- half-life
- time in which there is a 50 percent chance that a nucleus will decay
- Heisenberg uncertainty principle
- fundamental limit to the precision with which pairs of quantities such as momentum and position can be measured
- hydrogen-like atom
- any atom with only a single electron
- isotope
- nuclei having the same Z and different N’s
- liquid drop model
- model of the atomic nucleus (useful only to understand some of its features) in which nucleons in a nucleus act like atoms in a drop
- mass number
- number of nucleons in a nucleus
- nuclear fission
- reaction in which a nucleus splits
- nuclear fusion
- reaction in which two nuclei are combined, or fused, to form a larger nucleus
- nucleons
- particles found inside nuclei
- planetary model of the atom
- model of the atom that shows electrons orbiting like planets about a Sun-like nucleus
- proton-proton cycle
- combined reactions and that begins with hydrogen and ends with helium
- rad
- amount of ionizing energy deposited per kilogram of tissue
- radioactive
- substance or object that emits nuclear radiation
- radioactive dating
- application of radioactive decay in which the age of a material is determined by the amount of radioactivity of a particular type that occurs
- radioactive decay
- process by which an atomic nucleus of an unstable atom loses mass and energy by emitting ionizing particles
- radioactivity
- emission of rays from the nuclei of atoms
- radiopharmaceutical
- compound used for medical imaging
- relative biological effectiveness (RBE)
- number that expresses the relative amount of damage that a fixed amount of ionizing radiation of a given type can inflict on biological tissues
- roentgen equivalent man (rem)
- dose unit more closely related to effects in biological tissue
- Rutherford scattering
- scattering of alpha particles by gold nuclei in the gold foil experiment
- Rydberg constant
- a physical constant related to atomic spectra, with an established value of
- scintillator
- radiation detection method that records light produced when radiation interacts with materials
- strong nuclear force
- attractive force that holds nucleons together within the nucleus
- tagged
- having a radioactive substance attached (to a chemical compound)
- therapeutic ratio
- the ratio of abnormal cells killed to normal cells killed
- transmutation
- process of changing elemental composition