You will probably be familiar with the term half-life in connection with radioactive decay. But do you also know what is behind it? Here you can find out using an example.
The half-life describes the period of time that is necessary until an exponentially decreasing value has halved. In the case of radioactive substances, 50% of the atomic nuclei have been converted into another nucleus, which in turn can be radioactive, with the emission of radiation.
- An example from the animal world could be the extermination of an animal species without intervention. Suppose the animal is a tiger or an elephant. Tigers have very valuable fur, elephants have ivory tusks, which are very popular.
- In the beginning, very few poachers will hunt and hunt the animals. You can sell the skins or the tusks in the market for a lot of money. This attracts more hunters who see how easy and quick it is to make easy money.
- This process repeats itself, the number of hunters will continue to increase and the population of animals will continue to decrease. At some point the time will come when only half of the original animals are still alive. The time that has passed by then is the half-life.
In reality, of course, measures are being taken to protect these threatened species.
With decay functions, a wide variety of decay processes, such as radioactive ...
Another example of half-life
Example 2: The half-life of radioactive substances that were released in the reactor accidents at Chernobyl or Fukushima is particularly interesting and important.
- Many are not aware that such substances have half-lives of several decades. The Chernobyl explosion released several trillion becquerels of activity. The soils, the atmosphere and the biomass in this region will therefore be contaminated for centuries. Houses and entire areas of land will no longer be habitable for a long time.
- The radioactive cesium-137 in particular has a half-life of around 30 years.
- In the case of radioactive decays, one can only speak of a probability of the transformation of a nucleus in a unit of time. In this context one speaks of a decay constant.
In the case of radioactive decay, do not forget: the half-life is reached after several decades, however, due to the large initial release of radioactive substances, the environment is still strong contaminated!