Question

The half-life of carbon-14 is 5730 years. Explain how to figure out the age of a substance that has 25% carbon-14 remaining. A) Multiply 25% times 5730 years since only 25% of the carbon remains. B) Divide 5730 years by 2 since carbon has gone through two half-lives. C) Multiply 5730 years by 2 since two half-lives have gone by for carbon. D) Multiply 4 times 5730 years since carbon has gone through 4 half-lives.

Answer 1

Answer:  C) Multiply 5730 years by 2 since two half-lives have gone by for carbon.

Explanation:

Multiply 5730 years by 2 since two half-lives have gone by for carbon. 5730 years will go by and 50% will remain. When 25% is remaining, another 5730 years will have passed. Therefore, multiply 5730 years by 2.

Answer 2

Answer:

C

Explanation:

25% is two half lives.

Each half life requires 5730 years.

So two half lives requires  

2

×

5730

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