WebThe becquerel (English: / b ɛ k ə ˈ r ɛ l /; symbol: Bq) is the unit of radioactivity in the International System of Units (SI). One becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second.For applications relating to human health this is a small quantity, and SI multiples of the unit are commonly used. ...

WebEnvironmental radioactivity is produced by radioactive materials in the human environment.While some radioisotopes, such as strontium-90 (90 Sr) and technetium-99 (99 Tc), are only found on Earth as a result of human activity, and some, like potassium-40 (40 K), are only present due to natural processes, a few isotopes, e.g. tritium (3 H), result …

WebThe sievert (symbol: Sv) is a unit in the International System of Units (SI) intended to represent the stochastic health risk of ionizing radiation, which is defined as the probability of causing radiation-induced cancer and genetic damage.The sievert is important in dosimetry and radiation protection.It is named after Rolf Maximilian Sievert, a Swedish medical …

WebThe Chernobyl disaster (also called the Chornobyl disaster) was a nuclear accident that occurred on 26 April 1986 at the No. 4 reactor in the Chernobyl Nuclear Power Plant, near the city of Pripyat in the north of the Ukrainian SSR in the Soviet Union. It is one of only two nuclear energy accidents rated at seven—the maximum severity—on the International …

WebAcute radiation syndrome (ARS), also known as radiation sickness or radiation poisoning, is a collection of health effects that are caused by being exposed to high amounts of ionizing radiation in a short period of time. Symptoms can start within an hour of exposure, and can last for several months. Early symptoms are usually nausea, vomiting and loss of appetite.

WebKraftwerk (German: [ˈkʁaftvɛɐ̯k], lit. "power station") is a German band formed in Düsseldorf in 1970 by Ralf Hütter and Florian Schneider.Widely considered innovators and pioneers of electronic music, Kraftwerk were among the first successful acts to popularize the genre.The group began as part of West Germany's experimental krautrock scene in the …

WebHistory of discovery. The first gamma ray source to be discovered was the radioactive decay process called gamma decay.In this type of decay, an excited nucleus emits a gamma ray almost immediately upon formation. Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900, while studying radiation emitted from …

Web放射能 （ ほうしゃのう 、 （ 英: Radioactivity ）とは、放射性同位元素が放射性崩壊を起こして別の元素に変化する性質（能力）を言う 。 なお、放射性崩壊に際しては放射線の放出を伴う。. 放射能は、単位時間に放射性崩壊する原子の個数（単位：ベクレル [Bq]）で計 …

WebAlpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and thereby transforms or 'decays' into a different atomic nucleus, with a mass number that is reduced by four and an atomic number that is reduced by two. An alpha particle is identical to the nucleus of a helium-4 atom, which consists of …

WebAntoine Henri Becquerel (/ ˌ b ɛ k ə ˈ r ɛ l /; 15 December 1852 – 25 August 1908) was a French engineer, physicist, Nobel laureate, and the first person to discover evidence of radioactivity.For work in this field he, along with Marie Skłodowska-Curie and Pierre Curie, received the 1903 Nobel Prize in Physics.The SI unit for radioactivity, the becquerel …