Question

Which one of the following noble gases is not found in atmosphere ?

• A. Rn
• B. Kr
• C. Ne
• D. Ar

Answer 1

Answer: (A)

Rn

Answer 2

All the noble gases except radon occur in the atmosphere. Xenon and radon are the rarest elements of the group. Radon is obtained as a decay product of 226Ra.

$\longrightarrow$+ ${ } _ { 2 } ^ { 4 } \mathrm { He }$