Humber/Ontario Real Estate Course 3 Exam Practice

How can radon gas enter residential buildings?

1. Through cracks in basement floors and walls

2. Thrives in damp upper levels

3. Flows with electricity

4. Leaks from plumbing systems

5. Seeps in through poorly sealed windows

6. Emerges from decaying organic matter

The correct answer is: Through cracks in basement floors and walls

Radon gas is known to enter residential buildings primarily through cracks in basement floors and walls. This occurs because radon is a naturally occurring radioactive gas that originates from the decay of uranium found in soil and rock underground. When soil gas, containing radon, builds up in the ground beneath a building, it can diffuse into the lower levels of the structure, particularly through any openings, such as cracks. This process highlights the importance of proper building design and construction techniques to minimize potential radon entry. Homes with basements or those built on slab foundations are particularly susceptible to radon intrusion if not properly ventilated or sealed. In contrast, the other options do not accurately describe how radon typically enters buildings. For instance, while damp conditions can contribute to mold growth or other indoor air quality issues, they do not directly correlate with radon's entry. Radon is not linked to electricity flow or plumbing issues and does not seep in through poorly sealed windows, which are more likely to allow outdoor air rather than soil gas. Lastly, while organic matter can produce gases, radon's presence is specifically tied to uranium decay found in geological materials rather than from decaying organic materials.