radioactive decay

(redirected from Decay rate)
Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
Related to Decay rate: radioactive decay rate

radioactive decay

the disintegration of the nucleus of an unstable nuclide by the spontaneous emission of charged particles, photons, or both.

radioactive decay

The continual loss of energy by radioactive substances. Disintegration of the nucleus by the emission of alpha, beta, or gamma rays eventually results in the complete loss of radioactivity. The time required for some materials to become stable may be minutes and, for others, thousands of years.
See: half-life
See also: decay

radioactive

characterized by radioactivity.

radioactive decay
spontaneous decomposition of the nuclei of the atoms of radioactive substances. Measured as the proportion of the atoms in a radionuclide that decompose per unit of time, usually stated as the half-life of that particular isotope.
radioactive fallout
dissemination of radioactive substances through the atmosphere and deposition on the environment generally; causes radiation injury.
radioactive isotope
radionuclide. A radioactive nuclide, e.g. radioactive iodine or strontium.
radioactive tracer
see radioactive tracer.
References in periodicals archive ?
New precision measurement of the decay rate of singlet positronium.
A series of test chamber experiments was then performed in which concentration decay rates were determined from continuously monitoring aerosol concentration at a particular location in the room.
Because the newly observed rate is considerably faster than the predicted rate, Moe suggests that Turkevich and his co-workers may have overlooked some background sources of plutonium-238 that would contribute to the observed decay rate.
Wind speed and wind direction changes resulted in slight variations in the decay rate in rooms with exterior walls impacted by the wind and with "leaky" conditions.
In the chamber experiment, the fractional aerosol removal efficiency is calculated from the aerosol decay rates observed for three cases: background case (no filter and no ion generation), filter mounted but without ion generation, filter and ion generation active.
The neutron decay rate is and ~[1 + a [beta] cos(Vev)] and (1/[beta])(d ln(Y)/da) approaches [+ or -]1 for small and large values of TOF, where cos(Vev) = [+ or -]1, as expected.
The researchers used a variety of methods including the decay rate of uranium and thorium, helium in the minerals apatite and zircon.
American Indians continue to live in communities where there is an up to 90% tooth decay rate.
However, all of the studied VOC-species showed a faster decay rate when the UV-light was on, compared to the case with UV-light off.
In fact, these studies find hints that decay rate depends on time of year, implying that perhaps the Earth's distance from the sun somehow exerts an influence, as Davide Castelvecchi describes in this issue (Page 20).
n] for the free neutron decay rate is given by the formula
The annual decay rate of email addresses costs marketers billions of dollars each year in wasted marketing, customer replacement, and opportunity costs from lost client relationships.