Which of the following is most likely the source of the radon found in a house?

• A. Use of chlorine-based cleaning products
• B. Decay of uranium in the soil beneath the house
• C. Combustion of natural gas in household appliances
• D. Leaching from copper plumbing pipes

Answer: (B)

Verified step by step guidance

1. Understand that radon is a radioactive noble gas that originates from the natural radioactive decay of uranium present in the Earth's crust.
2. Recognize that radon gas is produced underground as uranium decays through a series of steps, eventually forming radon, which can migrate through soil and enter buildings.
3. Evaluate the options: chlorine-based cleaning products and combustion of natural gas do not produce radon, as radon is not a product of chemical reactions or combustion processes.
4. Consider that leaching from copper plumbing pipes is unrelated to radon production, since radon is a gas formed from radioactive decay, not from metal corrosion or leaching.
5. Conclude that the most likely source of radon found in a house is the decay of uranium in the soil beneath the house, as this is the natural and common origin of radon gas indoors.