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In nuclear science a decay chain refers to the predictable series of radioactive disintegrations undergone by the nuclei of certain unstable chemical elements. Radioactive isotopes do not usually decay directly to stable isotopes, but rather into another radioisotope. The isotope produced by this radioactive emission then decays into another ...
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha, beta, and gamma decay.
Radioactive decay is the process in which an unstable atomic nucleus loses energy by emitting ionizing particles and radiation. This decay, or loss of energy, results in an atom of one type (called the parent nuclide ) transforming to an atom of a different type (called the daughter nuclide ).
Since nuclear chain reactions may only require natural materials (such as water and uranium, if the uranium has sufficient amounts of 235 U), it was possible to have these chain reactions occur in the distant past when uranium-235 concentrations were higher than today, and where there was the right combination of materials within the Earth's crust.
In nuclear physics and nuclear chemistry, a nuclear reaction is a process in which two nuclei, or a nucleus and an external subatomic particle, collide to produce one or more new nuclides. Thus, a nuclear reaction must cause a transformation of at least one nuclide to another.
220 Rn occurs in minute quantities as an intermediate step in the decay chain of 232 Th, also known as the thorium series, which eventually decays into stable 208 Pb. Radon was discovered in 1899 by Ernest Rutherford and Robert B. Owens at McGill University in Montreal , and was the fifth radioactive element to be discovered.
Decay products are important in understanding radioactive decay and the management of radioactive waste. For elements above lead in atomic number, the decay chain typically ends with an isotope of lead or bismuth. Bismuth itself decays to thallium, but the decay is so slow as to be practically negligible.
The valley of stability can be helpful in interpreting and understanding properties of nuclear decay processes such as decay chains and nuclear fission. The uranium-238 series is a series of α (N and Z less 2) and β− decays (N less 1, Z plus 1) to nuclides that are successively deeper into the valley of stability.