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The half-life of carbon-14 is 70,000 years. If there was originally 100 g. of carbon-14 in a fossil, and now there is only 25 g, how old is the fossil?
What is 140,000 years. 100 to 50 g is the first half-life= 70,000 years. 50 g divided in half is 25 g= another 70,000 years, which in total is 140,000 years