Question

A characteristic feature of radioactive isotopes is their unique half-life, representing the duratio

required for half of the isotope to decay. The table presents the half-lives of four isotopes.

Isotope. half-life ( years)
Carbon-14. 5.7 x 10^3
Potassium-40 1.3 x10^9
Radon-222. 1.0 x 10^-2
Thorium-232 1.4 x 10^10
Answer
Using this data, which isotope would scientists avoid using for dating a fossil?-

(1 point)

thorium-232

Oradon-222

carbon-14

potassium-40
Answered by GPT-4o mini
Based on the information provided, here are the half-lives of the four isotopes:

1. **Carbon-14**: \( 5.7 \times 10^3 \) years (or 5,700 years)
2. **Potassium-40**: \( 1.3 \times 10^9 \) years (or 1.3 billion years)
3. **Radon-222**: \( 1.0 \times 10^{-2} \) years (or 0.01 years, which is about 8.76 hours)
4. **Thorium-232**: \( 1.4 \times 10^{10} \) years (or 14 billion years)

### Key Points:
- **Carbon-14** is commonly used in radiocarbon dating for archaeological and geological samples, as its half-life is suitable for dating more recent materials.
- **Potassium-40** is often used in geological dating and can date materials that are millions to billions of years old.
- **Radon-222** has a very short half-life, making it less useful for dating purposes but significant in the study of radioactivity and health risks related to its presence in buildings.
- **Thorium-232** has a long half-life and is useful in studying the age of the Earth and in the field of nuclear science.

If you need further analysis or specific applications for these isotopes, feel free to ask!
Answered by GPT-4o mini
Scientists would avoid using **Radon-222** for dating a fossil.

This is because Radon-222 has a very short half-life of only about 0.01 years (approximately 8.76 hours), which means it decays too quickly to be useful for dating fossils that are typically thousands to millions of years old. In contrast, isotopes like Carbon-14, Potassium-40, and Thorium-232 have longer half-lives that make them suitable for dating various types of geological and archaeological samples.