Lead-206

Definition

Lead-206 is a stable isotope of lead, meaning it does not undergo radioactive decay. It is the final product of the uranium-238 decay chain, making it an important isotope in the study of radioactive half-life and activity.

5 Must Know Facts For Your Next Test

1. Lead-206 is the end product of the uranium-238 decay chain, which involves a series of radioactive transformations over billions of years.
2. The half-life of uranium-238 is approximately 4.5 billion years, making it a useful tool for dating the age of the Earth and other geological formations.
3. The stability of lead-206 allows it to be used as a reference point for measuring the age of rocks and minerals through radiometric dating techniques.
4. The radioactive decay of uranium-238 and its intermediate products, such as radium-226 and radon-222, can be used to determine the age of geological samples.
5. The activity of lead-206 is negligible compared to the initial activity of uranium-238, as it represents the final, stable product of the decay chain.

Review Questions

• Explain the significance of lead-206 in the context of the uranium-238 decay chain.
  • Lead-206 is the final, stable isotope in the uranium-238 decay chain. As the end product of this radioactive decay process, which takes billions of years to complete, lead-206 is an important marker for determining the age of geological samples through radiometric dating techniques. The stability of lead-206 contrasts with the radioactive nature of the preceding isotopes in the chain, making it a reliable indicator of the passage of time and the age of the Earth and other planetary bodies.
• Describe how the half-life of uranium-238 is used to measure the age of rocks and minerals.
  • The long half-life of uranium-238, approximately 4.5 billion years, makes it a valuable tool for radiometric dating. By measuring the relative abundance of uranium-238 and its decay products, such as lead-206, scientists can determine the age of a geological sample. The gradual transformation of uranium-238 into lead-206 over billions of years provides a natural clock that can be used to calculate the age of the sample. This process, known as radiometric dating, is a crucial technique for understanding the geological history of the Earth and the solar system.
• Analyze the relationship between the activity of lead-206 and the initial activity of uranium-238 in the context of radioactive decay.
  • The activity of lead-206, the final stable isotope in the uranium-238 decay chain, is negligible compared to the initial activity of uranium-238. This is because the radioactive decay of uranium-238 and its intermediate products, such as radium-226 and radon-222, gradually reduces the overall activity over billions of years. As the end product, lead-206 represents the accumulated result of this decay process, with its own activity being insignificant compared to the initial radioactivity of the uranium-238 sample. This relationship between the activity of the parent and daughter isotopes is a fundamental principle in understanding radioactive half-life and the applications of radiometric dating.

Related terms

Radioactive Decay: The spontaneous process by which an unstable atomic nucleus loses energy by emitting radiation in the form of particles or electromagnetic waves.

Uranium-238 Decay Chain: The series of radioactive decay processes that begin with the unstable isotope uranium-238 and eventually lead to the stable isotope lead-206.

Radiometric Dating: A technique used to determine the age of rocks and minerals based on the known decay rates of radioactive isotopes.