ANSWER:
Radon is a "naturally occurring gas" which is found in most soils and rocks and also can cause "lung cancer".
Step-by-step explanation:
- Radon is a "chemical element" which is found to be tasteless, odorless, colorless, and highly radioactive. Due to the radioactive nature of radon, it is very dangerous and causes lung cancer.
- Apart from the soils and rocks, the residues of radon could be found on petroleum, spring water and hot springs.