Potassium-40 Decays to Argon-40 with a Half-Life of 1

question 142

Multiple Choice

Potassium-40 decays to argon-40 with a half-life of 1.27 × 10⁹ yr. The age of a mineral sample that has a mass ratio of ⁴⁰Ar to ⁴⁰K of 0.330 is ________ yr.

• A)3.85 × 10⁹
• B)1.77 × 10⁹
• C)2.55 × 10⁹
• D)3.62 × 10⁸
• E)5.23 × 10⁸

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