radioactivity


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Related to radioactivity: half life, artificial radioactivity

ra·di·o·ac·tiv·i·ty

 (rā′dē-ō-ăk-tĭv′ĭ-tē)
n.
1. Spontaneous emission of radiation, either directly from unstable atomic nuclei or as a consequence of a nuclear reaction.
2. The radiation, including alpha particles, nucleons, electrons, and gamma rays, emitted by a radioactive substance.

radioactivity

(ˌreɪdɪəʊækˈtɪvɪtɪ)
n
(Nuclear Physics) the spontaneous emission of radiation from atomic nuclei. The radiation can consist of alpha, beta, and gamma radiation

ra•di•o•ac•tiv•i•ty

(ˌreɪ di oʊ ækˈtɪv ɪ ti)

n.
the phenomenon, a property of certain elements, of spontaneously emitting radiation resulting from changes in the nuclei of atoms of the element.

ra·di·o·ac·tiv·i·ty

(rā′dē-ō-ăk-tĭv′ĭ-tē)
The emission of radiation by unstable atomic nuclei undergoing radioactive decay.
Did You Know? Within the nuclei of stable atoms, such as those of lead, the force binding the protons and neutrons to each other individually is great enough to hold the nuclei together as a whole. In the nuclei of other atoms, especially of heavy ones such as uranium atoms, this energy is not great enough, and the nuclei are unstable. An unstable nucleus gives off particles and energy in a process known as radioactivity. When enough particles and energy have been given off to create a new, stable nucleus (often the nucleus of an entirely different element), the radioactivity ceases. For example, uranium 238, a very unstable element, goes through 18 different stages of decay before finally turning into a stable isotope of lead, lead 206. (Some of the intermediate stages include the heavier elements thorium, radium, radon, and polonium.) All known elements with an atomic number greater than 83 (bismuth) are radioactive, and many isotopes of elements with lower atomic numbers are radioactive too.

radioactivity

The spontaneous emission of radiation, generally alpha or beta particles, often accompanied by gamma rays, from the nuclei of an unstable isotope.

radioactivity

the state, property, or process of being radioactive.
See also: Radiation

radioactivity

1. The emission of rays and subatomic particles from the nuclei of certain elements decaying into others, notably uranium and its decay products, down to, but excluding, lead. Radioactivity from nuclear bombs and installations, and even certain rocks, can injure living tissues.
2. The spontaneous disintegration of certain isotopes accompanied by the emission of radiation (a-rays, b-rays, c-rays).
3. The emission of subatomic particles and rays due to the disintegration of the atomic nuclei of certain isotopes of some elements.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.radioactivity - the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay
corpuscular radiation, particulate radiation - a stream of atomic or subatomic particles that may be charged positively (e.g. alpha particles) or negatively (e.g. beta particles) or not at all (e.g. neutrons)
emission - the release of electrons from parent atoms
Translations
إشعاعِيَّه
radioaktivita
radioaktivitet
radioaktivitás
geislavirkni
rádioaktivita
radyoaktivite

radioactivity

[ˈreɪdɪəʊækˈtɪvɪtɪ] Nradiactividad f, radioactividad f

radioactivity

[ˌreɪdiəʊækˈtɪvɪti] nradioactivité fradio alarm nradio-réveil mradio alarm clock nradio-réveil m

radioactivity

[ˌreɪdɪəʊækˈtɪvɪtɪ] nradioattività

radioactive

(reidiəuˈӕktiv) adjective
1. (of some substances, eg uranium) giving off rays which can be dangerous, but which can also be used in eg medicine. radioactive metals.
2. containing radioactive substances. radioactive waste/dust.
ˌradioacˈtivity noun

ra·di·o·ac·tiv·i·ty

n. radiactividad, propiedad de ciertos elementos de producir radiaciones.

radioactivity

n radiactividad f
References in periodicals archive ?
Keeping this in mind, today marks the anniversary of the day when Henri Becquerel discovered radioactivity in 1896.
The total radioactivity released into the environment was estimated at 770,000 teraBq, or approximately 15% of that released by the Chernobyl accident.
Due to its intense radioactivity, its chemistry has mostly been investigated on the trace scale only.
RUSSIAN authorities have confirmed reports of a spike in radioactivity in the air over the Ural Mountains.
The radioactivity was discovered after monitors in Italy picked up on the ruthenium-106 isotope in the air.
Cloud with low radioactivity has passed over Europe in recent weeks, according to data from the French Institute of Nuclear Safety.
The Energy Department said Wednesday that most of the tunnel will be filled with grout, which will stabilize the tunnel and help contain radioactivity.
The IAEA and the Nuclear Regulatory Authority of Argentina have held a regional workshop in Buenos Aires from 21 to 23 March 2017, to discuss the application of current international standards for managing radioactivity in food, drinking water and commodities in non-emergency situations.
Environmental Protection Agency (EPA) last issued guidance on radioactivity levels allowed in drinking water in a 1992 "Protective Action Guide.
Some decay products approach the same radioactivity concentration as the parent radionuclide in a matter of days, while others do so over many decades.
FRACKING will increase water radioactivity but not pose a threat to public health, a study has warned.
Tests show that wastewater from gas field landfills contains radioactivity.

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