What are some examples of isotopes with long half-lives?

Some examples of isotopes with long half-lives include Uranium-238, Thorium-232, and Potassium-40.

Uranium-238 is one of the most well-known isotopes with a long half-life, which is about 4.5 billion years. This isotope is commonly found in the Earth's crust and is used in dating rocks and geological formations. Its long half-life makes it particularly useful for understanding the age of the Earth and the timing of geological events.

Thorium-232 is another isotope with a very long half-life, approximately 14 billion years. Like Uranium-238, Thorium-232 is also found naturally in the Earth's crust. It is used in various applications, including as a potential fuel for nuclear reactors. Its long half-life means it remains radioactive for a very long time, which is both a challenge and an opportunity for its use in energy production.

Potassium-40 has a half-life of about 1.25 billion years and is found in many minerals and rocks. It is particularly important in the field of radiometric dating, where it is used to date ancient rocks and fossils. Potassium-40 decays into Argon-40, and by measuring the ratio of these isotopes in a sample, scientists can determine its age.

These isotopes are significant in various scientific fields, including geology, archaeology, and nuclear physics. Their long half-lives allow scientists to study processes and events that occurred millions or even billions of years ago, providing valuable insights into the history of our planet and the universe.