The half-life of a radioactive material refers to the time it takes for half of a sample of that material’s unstable atomic nuclei to undergo radioactive decay and transform into a more stable form. In other words, it’s the duration it takes for the initial quantity of radioactive substance to reduce by half due to the emission of particles or radiation. The concept of half-life is crucial in understanding the rate of decay and the behavior of radioactive substances over time. Different radioactive materials have unique half-lives, ranging from fractions of a second to millions of years, and this property is utilized in various fields such as radiometric dating, medical imaging, and nuclear energy.
| Isotope | Half-Life |
|---|---|
| Carbon-14 | 5,730 years |
| Uranium-238 | 4.468 billion years |
| Potassium-40 | 1.25 billion years |
| Radon-222 | 3.8 days |
| Cobalt-60 | 5.27 years |
| Iodine-131 | 8.02 days |
| Strontium-90 | 28.8 years |
| Technetium-99m | 6 hours |
| Plutonium-239 | 24,100 years |
| Iodine-131 | 8.02 days |
| Strontium-90 | 28.8 years days |
| Technetium-99m | 6 hours |
| Plutonium-239 | 24,100 years |
Radioactivity is the spontaneous emission of particles or radiation from unstable atomic nuclei, aiming to achieve stability, and is a fundamental property of certain elements.
Radioactive dating is a method of determining the age of objects or materials by measuring the decay of radioactive isotopes present within them, using the known half-lives of these isotopes as a clock to estimate the time since their formation.