Uranium (element)
鈾 centers on the metallic element uranium. It is a specialized character for this chemical element, with no broader conceptual extensions.
鈾 is a modern coined character for uranium, combining the metal radical 金 with the phonetic 由 (チュウ/ユウ). It was created to represent the element in Chinese and later adopted into Japanese.
The left side 金 means metal, and the right side 由 looks like a container. Picture a heavy metal container holding radioactive uranium.
For チュウ, imagine a metal chew toy made of uranium: chew -> チュウ, but don't actually chew it!