Multiple Choice
Radioactive dating: Today, the uranium found on Earth contains 0.720% 235U (with a half-life of 0.700 billion years) and 99.28% 238U (with a half-life of 4.50 billion years) . At a time 2.20 billion years ago, what percent of the uranium on Earth was 238U (assuming that no other uranium isotopes were present) ?
A) 95.6%
B) 2.18%
C) 6.29%
D) 8.68%
E) 4.53%
Correct Answer:
Verified
Correct Answer:
Verified
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