Question

a lump of carbon - 14 decays at a rate of 10% every thousand years. below is a graph of this decay.
if there is currently 10 grams of carbon - 14, as shown, about how long would it take for there to be 5 grams of carbon - 14?
○ a. about 7 thousand years
○ b. about 14 thousand years

Explanation:

Step1: Locate 10 grams on the y - axis

Find the point where the y - value is 10 grams.

Step2: Locate 5 grams on the y - axis

Find the point where the y - value is 5 grams.

Step3: Trace horizontally and vertically on the graph

From the 10 - gram point, trace the curve until the y - value is 5 grams. Then trace vertically to the x - axis.

Answer:

A. about 7 thousand years