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Question:

The noble gas that does NOT occur in the atmosphere is: He, Ne, Kr, Ra

He

Kr

Ne

Ra

Solution:

The correct option is Ra. In the question, the noble gas is asked, which does not exist in the atmosphere, and the answer given is Ra. Ra is an alkaline earth metal, not a noble gas; it should be Rn. It is a printing error in the JEE main paper.