Question

You find a fossil, and through careful study you find that only one-sixteenth of the carbon-14 that it once contained is still remaining in it. Carbon-14 has a half-life of approximately 5700 years. You can conclude that the age of the fossil is about __________.

a. 4 × 5700 yr = 22,800 years
b. 16 × 5700 yr = 91,200 years
c. 1/16 × 5700 yr = 356 years
d. 5 × 5700 yr = 28,500 years

Answer 1

The answer is: A) 4 × 5,700 years = 22,800 years

Step-by-step explanation:

Each half-life of Carbon-14 is approximately 5,700 years.

The amounts of Carbon-14 remaining in a specimen sample are:

• After one half life only half of the original Carbon-14 amount remains.
• After two half lives only one fourth of the original Carbon-14 amount remains.
• After three half lives only one eight of the original Carbon-14 amount remains.
• After four half lives only sixteenth of the original Carbon-14 amount remains.

Since only one sixteenth of the original Carbon-14 remained, we can conclude that the fossil is four half lives old.

All we do now is multiply 4 x 5,700 years (half life of Carbon-14) = 22,800 years