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sary sary
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10 years ago
If a martian rock is found containing 40% parent nuclei. How old is it based on your average results assuming each cycle is 1 billion years.
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Staff Member
3 years ago
(0.5)^N = 0.4

N log 0.5 = log 0.4

N = log 0.4 / log 0.5

N = 1.322

N = number of half-lives elapsed

The rock is 1.322e9 years old.
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