Half-Life & Risk (AQA GCSE Physics): Revision Notes
📚 Revision Notes
4.3.2 Half-Life & Risk
Half-Life of Radioactive Isotopes
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The half-life of a radioactive isotope is the time it takes for half of the radioactive atoms in a sample to decay. This property is unique to each isotope and can vary significantly.
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The half-lives of radioactive isotopes can range from fractions of a second to millions of years. Despite this variability, all isotopes will gradually decrease in radioactivity over time.
Associated Hazards
- Risk Assessment: The half-life of a radioactive isotope plays a crucial role in determining its potential risk.
- Long Half-Lives: Isotopes with long half-lives remain radioactive for extended periods, posing a prolonged risk. These isotopes can be dangerous because they emit radiation over a long time, increasing the potential for exposure.
- Short Half-Lives: Isotopes with short half-lives decay quickly, reducing their radioactivity in a shorter time. While they may emit intense radiation initially, the risk diminishes rapidly as they decay.