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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.
Again, a key feature of using radioactivity in life science applications is that it is a quantitative technique, so PET/SPECT not only reveals where a radiolabelled molecule is but how much is there. Radiobiology (also known as radiation biology) is a field of clinical and basic medical sciences that involves the study of the action of ...
Radiation is often categorized as either ionizing or non-ionizing depending on the energy of the radiated particles. Ionizing radiation carries more than 10 electron volts (eV), which is enough to ionize atoms and molecules and break chemical bonds. This is an important distinction due to the large difference in harmfulness to living organisms.
The unit of radioactivity from the System International of units (SI system) is the becquerel (Bq) defined as the radioactive decay or disintegration of one radionuclide per second. Radioactivity is a measure of the total, local rate of radionuclides decaying per unit time and is dependent upon the total number of atoms, decay constants , and ...
The radiation chemistry controls much of radiation biology as radiation has an effect on living things at the molecular scale. To explain it another way, the radiation alters the biochemicals within an organism, the alteration of the bio-molecules then changes the chemistry which occurs within the organism; this change in chemistry then can ...
The distribution coefficient K d is the ratio of the soil's radioactivity (Bq g −1) to that of the soil water (Bq ml −1). If the radioactivity is tightly bonded to by the minerals in the soil then less radioactivity can be absorbed by crops and grass growing in the soil. Cs-137 K d = 1000; Pu-239 K d = 10000 to 100000; Sr-90 K d = 80 to 150 ...
Artificial radioactive affliction to Earth’s environment began with nuclear weapon testing during World War II, but did not become a prominent topic of public discussion until the 1980s. The Journal of Environmental Radioactivity (JER) was the first collection of literature on the subject, and its inception was not until 1984. [ 2 ]
In nuclear physics, atomic physics, and nuclear chemistry, the nuclear shell model utilizes the Pauli exclusion principle to model the structure of atomic nuclei in terms of energy levels. [1]