Wood from a sample of carbon-14 in a living tree has an activity of 120 Bq. Wood found in an archaeological dig has an activity of 30 Bq. The half-life of carbon-14 is 5,730 years. Estimate the age of the dead wood.

What is a becquerel?

What is the half-life of a radioactive isotope?

What percentage of an original polonium sample will remain after three half-lives have passed?

A radioactive source’s activity falls from 8,000 counts per minute to 500 counts per minute in 20 hours. What is the half-life of the source?