A Geological Sample Is Found to Have a Pb-206/U-238 Mass

question 15

Multiple Choice

A geological sample is found to have a Pb-206/U-238 mass ratio of 0.337/1.00.Assuming there was no Pb-206 present when the sample was formed,how old is it? The half-life of U-238 is 4.5 × 10⁹ years.

• A) 7.3 × 10¹¹ years
• B) 1.4 × 10¹⁰ years
• C) 2.4 × 10¹⁰ years
• D) 2.1 × 10⁹ years
• E) 7.1 × 10⁹ years