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Home Q & A Board Science-Related Homework Help Geography and Earth Sciences
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keelyhawkins keelyhawkins
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6 years ago

A rock sample containing an isotope with a half-life of 28 million years has an initial mass of 184 grams. How much
  time has elapsed after three half-lives?
  a. 6.5 million years
  b. 9.3 million years
  c. 32 million years
  d. 56 million years
  e. 84 million years
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leg17leg17
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6 years ago
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keelyhawkins Author
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6 years ago
Thank you, thank you, thank you!
momochiime
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Yesterday
this is exactly what I needed
Zacellison
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2 hours ago
Thanks
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