Question

An unreactive gas. In the comic book world, a mineral containing this element could weaken Superman. In the real world, a radioactive form of this element is a by-product of most nuclear explosions and its presence in the atmosphere can indicate which nations are testing nuclear weapons.

a. Krypton
b. Xenon
c. Radon
d. Neon

Answer 1

The correct answer to the question is c. Radon, a noble gas that is a by-product of nuclear decay and can indicate nuclear weapon tests.

Step-by-step explanation:

The unreactive gas being described is krypton, which in the comic book world is a component of the fictional mineral 'Kryptonite' that weakens Superman. In the real world, the radioactive form of an element that matches the provided clues is radon.

Radon is indeed a noble gas that is a by-product of the decay of uranium and thorium, and its presence in the atmosphere can indicate nuclear weapon tests. Therefore, the correct answer is c. Radon.