Samarium has a half-life of approximately 106 billion years. If you found a sample of samarium from the beginning of Earth's history, approximately 4.6 billion years ago, which would be the best approximation of the amount of parent isotope left in the rock?

Nearly 100 percent

50 percent

25 percent

Less than 10 percent

Question

Samarium has a half-life of approximately 106 billion years. If you found a sample of samarium from the beginning of Earth's history, approximately 4.6 billion years ago, which would be the best approximation of the amount of parent isotope left in the rock?

Nearly 100 percent

50 percent

25 percent

Less than 10 percent

anonymous · Answer

i would go with the first one since 4.6 is a small part of 106