sönderfallskedja

A sönderfallskedja, or decay chain, is a sequence of radioactive decays where one unstable atomic nucleus transforms into another, and then into another, and so on, until a stable nucleus is reached. This process occurs when an unstable isotope, known as the parent nuclide, undergoes radioactive decay to form a daughter nuclide. If the daughter nuclide is also radioactive, it will further decay into another daughter nuclide, creating a chain of transformations.

Radioactive decay can occur through several mechanisms, including alpha decay, beta decay (which includes beta-minus and beta-plus decay), and gamma decay. Each step in a sönderfallskedja involves a specific type of decay and the emission of particles or energy. For instance, in alpha decay, the nucleus emits an alpha particle (two protons and two neutrons), reducing its atomic number by two and its mass number by four. In beta-minus decay, a neutron is converted into a proton, emitting an electron and an antineutrino, increasing the atomic number by one while keeping the mass number the same.

The most common and well-known sönderfallskedjor are those involving heavy, unstable elements like uranium and thorium. For example, the uranium-238 sönderfallskedja begins with uranium-238 and proceeds through a series of intermediate radioactive isotopes, including thorium-234, protactinium-234, uranium-234, and radium-226, eventually ending with the stable isotope lead-206. Each nuclide in the chain has a characteristic half-life, which dictates the time it takes for half of the parent nuclide to decay. The overall duration of a sönderfallskedja is determined by the longest half-life of the isotopes within the chain. Understanding decay chains is crucial in fields like nuclear physics, geology (for radiometric dating), and nuclear medicine.