The half-life of carbon-14, which is used in dating archaeological finds, is 5730 yr.
a. Assume that 100% of the carbon-14 is present at time 0 yr, or x = 0. Write the equation that expresses the percentage of carbon-14 remaining as a function of time. (This should be the same equation you found in Lesson 5.6, Exercise 8a.)
b. Suppose some bone fragments have 25% of their carbon-14 remaining. What is the approximate age of the bones?
c. In the movie Raiders of the Lost Ark (1981), a piece of the Ark of the Covenant found by Indiana Jones contained 62.45% of its carbon-14. What year would this indicate that the ark was constructed in?
d. Coal is formed from trees that lived about 100 million years ago. Could carbon-14 dating be used to determine the age of a lump of coal? Explain your answer.