Radioactivity is the spontaneous transformation of unstable atomic nuclei accompanied by the emission of ionizing radiation, typically in the form of alpha particles (helium-4 nuclei), beta particles (electrons or positrons), and gamma rays (high-energy photons), as well as neutrinos in many decay modes. It is governed by quantum-mechanical nuclear processes and characterized statistically by decay constants and half-lives, following first-order kinetics. Radioactivity alters nuclide identity through changes in proton and neutron numbers, driving nuclei toward more energetically favorable configurations. It is fundamental in nuclear physics, radiochemistry, dosimetry, and applications such as radiometric dating, nuclear medicine, radiation therapy, reactor physics, and radiation protection research.
In 1989, the Soviet nuclear-powered attack submarine Komsomolets sank to the bottom of the Norwegian Sea, along with its nuclear reactor and two nuclear warheads onboard. Komsomolets was constructed with a titanium alloy ...
Scientists have long relied on tree rings to learn about ancient solar storms—rare bursts of high-energy particles from the sun that can disrupt satellites, power grids, and communication systems across the planet. When these ...
Planetary Sciences
Jan 29, 2026
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More than a half century after the U.S. ignited 67 atomic weapons in the central Pacific Ocean, a former Navy base in the Bay Area continues to carry that nuclear legacy.
Environment
Nov 10, 2025
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A new study has uncovered how tiny differences in boron atoms can help scientists better predict the long-term behavior of glass used to store hazardous waste. The findings, published in Environmental and Biogeochemical Processes, ...
Earth Sciences
Oct 15, 2025
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A new study from the University of Missouri is helping veterinarians and pet owners better understand how to treat thyroid cancer in dogs by studying how to improve treatment with a type of therapy called radioactive iodine. ...
Veterinary medicine
Sep 9, 2025
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Radioactive decay is a fundamental process in nature by which an unstable atomic nucleus loses energy by radiation. Studying nuclear decay modes is crucial for understanding properties of atomic nuclei. In particular, exotic ...
General Physics
Jul 21, 2025
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611
A team of researchers in France are building on fundamental experimental research undertaken in the Ukrainian Chornobyl exclusion zone with a new project in the Japanese Fukushima Prefecture to further our understanding of ...
Ecology
Jul 11, 2025
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67
The University of Jyväskylä (Finland), in collaboration with the Finnish Radiation and Nuclear Safety Authority (STUK), has developed a new type of handheld multi-purpose radiation detector that comprehensively detects all ...
General Physics
Apr 15, 2025
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384
Researchers at the Accelerator Laboratory of the University of Jyväskylä, Finland, precisely measured atomic masses of radioactive lanthanum isotopes and found an interesting feature in their nuclear binding energies. The ...
General Physics
Jan 31, 2025
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141
Nuclear fission reactors act as a key power source for many parts of the world and worldwide power capacity is expected to nearly double by 2050. One issue, however, is the difficulty of discerning whether a nuclear reactor ...
General Physics
Oct 1, 2024
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