70.4k views
5 votes
This exercise uses the radioactive decay model. A wooden artifact from an ancient tomb contains 80% of the carbon-14 that is present in living trees. How long ago was the artifact made? (The half-life of carbon-14 is 5730 years. Round your decay rate, r, to 6 decimal places. Then round your answer to nearest whole number)

1 Answer

2 votes

Final answer:

The artifact was made approximately 28,650 years ago. In the radioactive decay model, the half-life of carbon-14 is 5730 years, and since the artifact contains 80% of the carbon-14 present in living trees, we can use the decay rate formula to determine the age of the artifact.

Step-by-step explanation:

The artifact was made approximately 28,650 years ago.

In the radioactive decay model, the half-life of carbon-14 is 5730 years. Since the artifact contains 80% of the carbon-14 that is present in living trees, it means that 20% of the original carbon-14 has decayed. To determine the time it takes for 20% of carbon-14 to decay, we can use the formula:

r = 1 - (1/2)t/h

Where r is the decay rate, t is the time in years, and h is the half-life.

Substituting the given values, we have:

r = 0.20, h = 5730 years

By solving for t, we find:

t = h * log2(1 - r)

Rounding the decay rate to 6 decimal places as instructed, we have r = 0.200000.

Plugging in the values, we have:

t = 5730 * log2(0.800000)

After solving, we find that t is approximately 28,650 years.

User Freddy Smith
by
8.0k points