A piece of uranium can be made into nuclear explosive only after it is purified into uranium-235, because
A) it has to be soldered with lead for safety.
B) the other naturally occurring isotopes of uranium interfere with efficient chain reactions.
C) uranium-235 is the heaviest isotope known to mankind.
D) before purification, the uranium-235 nucleus will not split apart.

Question

Quizplus · Accepted Answer

The other naturally occurring isotopes of uranium, specifically uranium-238, absorb neutrons and do not efficiently participate in the chain reaction necessary for a nuclear explosion. Therefore, uranium-235 must be purified, typically through the process of isotope separation, before it can be used in a nuclear explosive.

A Piece of Uranium Can Be Made into Nuclear Explosive