Week 37 (May 6 - 10)

Reading: Radioactivity (still)

Key Topics:
radioactive decay, half life, radiocarbon dating


Homework Problems:
  1. Radon gas problem: Radon-222 is a radioactive as produced when radium-226 undergoes alpha decay. If it enters your house through cracks in walls and floors, it may get into the drinking water. Suppose 30 million radon atoms are trapped in the basement. The basement is sealed against further entry of the gas. The half-life of radon is 3.83 days. (a) How many atoms remain after 31 days? Find the activity, dN/dt, (b) just after the basement is sealed and (c) 31 days later. By the way, activity is measured in Becquerels (Bq).
  2. Dead sea scrolls problem: The dead sea scrolls, discovered in 1947, were dated by applying radiocarbon dating methods to the linen in which they were wrapped. Linen is made from a flax plant. A Carbon-14 activity of 0.18 Bq per gram of carbon was measured. What was the radiocarbon date of the scrolls?
General College Physics