Which noble gas is radioactive and is produced as a decay product of uranium and thorium?

Explanation

Radon is radioactive. It comes from uranium and thorium decay. Radon gas can build up in basements and cause health problems.

Argon, neon, and krypton are stable noble gases. They don’t decay or emit radiation.

Remember: Radon is dangerous because it’s radioactive and invisible. Test your home for radon gas.