Which colorless and odorless gas, produced by radioactive decay of Uranium-238, is considered to be a cancer-causing agent?
A. Hydrogen
B. Radon
C. Oxygen
D. Boron
B, radon is correct. Interestingly, it often collects in basements from radioactive decay of rocks such as granite that contain uranium. Because it is an unreactive noble gas and because it is denser than air it sits in basements and must be pumped out. It collects in human lungs and is the second leading cause of lung cancer behind smoking.
