What is the primary material used in the production of nuclear weapons?

The primary materials used in the production of nuclear weapons are uranium and plutonium. These two elements are essential due to their ability to undergo nuclear fission, a process where the nucleus of an atom splits into smaller parts, releasing a significant amount of energy.

Uranium, particularly the isotope Uranium-235, is naturally occurring and can be enriched to increase its fissionable content. Plutonium, on the other hand, is not found in sizable quantities in nature and is typically produced in nuclear reactors from uranium-238.

The other materials listed—lead, iron, and carbon—are not suitable for use as the main fissile material in nuclear weapons. While they may have roles in the construction or shielding of nuclear facilities and devices, they do not possess the necessary nuclear properties to be used in the actual fission process that is fundamental to nuclear weapon functionality.