Radioactivity
Convert between different units of radioactivity used in nuclear physics, medicine, and radiation safety
Radioactivity Converter
Convert between different units of radioactivity used in nuclear physics, medicine, and radiation safety
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About Radioactivity
Explore radioactivity units from nuclear physics, medicine, and radiation protection
Historical Context
The measurement of radioactivity began shortly after the discovery of radioactivity by Henri Becquerel in 1896. The curie (Ci) was one of the first units, defined in 1910 and named after Marie and Pierre Curie. It was originally defined as the activity of 1 gram of radium-226. As nuclear science advanced, the need for a more precise, standardized unit led to the introduction of the becquerel (Bq) in the 1970s as part of the International System of Units (SI). The becquerel represents one nuclear decay per second, making it directly tied to the physical process being measured, while the curie represents 3.7 × 10^10 decays per second (the approximate activity of 1 gram of radium-226).
Modern Standards
Today, the becquerel (Bq) is the standard SI unit for radioactivity, representing one nuclear disintegration per second. While the scientific community has widely adopted the becquerel, the curie and its subdivisions remain in common use in the United States, particularly in medicine and the nuclear industry. Regulatory bodies like the International Atomic Energy Agency (IAEA) and the Nuclear Regulatory Commission (NRC) provide conversion standards between these units. In scientific research, becquerels are preferred, while in nuclear medicine, both units are often used side by side. Environmental monitoring typically reports in becquerels, while historical data may still reference curies, requiring conversion for modern analysis.
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Conversion Reference
Quick reference for common radioactivity conversions