Multiple choice general knowledge science & technology

What is the heaviest of the naturally occuring Noble gases?

  1. Xenon

  2. Radon

  3. Helium

  4. Argon
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Radon (Rn, atomic number 86) is the heaviest naturally occurring noble gas with atomic mass 222. Xenon (131), Argon (40), and Helium (4) are all lighter. Radon is radioactive and occurs naturally from uranium decay, making it the heaviest in the noble gas group.

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