What very dense metal is used in industrial counterweights, high-density armor, and nuclear fuels?

The choice of uranium as the answer is primarily due to its unique properties that suit it for specific industrial applications, particularly in the context of nuclear energy. Uranium is a dense metal, with a density of about 19.1 g/cm³, making it significantly heavier than many other metals like lead and tungsten. This density is advantageous for use in high-density armor and counterweights, as it allows for a compact and effective solution in these applications.

Moreover, uranium's capability to undergo fission, where the nucleus splits to release a significant amount of energy, makes it essential for nuclear fuels. The efficiency of uranium in energy production stems from this reaction, which is a key feature that distinguishes it from other dense metals in the context of nuclear energy.

While lead is also dense and historically used in radiation shielding, it does not share the nuclear fission properties that make uranium crucial for nuclear fuel applications. Tungsten, although very dense and highly useful for armor and various industrial applications, lacks the nuclear characteristics necessary for it to be used as a nuclear fuel. Gold, while dense, is not used in industrial contexts like counterweights or nuclear energy due to its rarity and cost.

In summary, uranium is distinctively suited for applications that require a combination of