Yttrium Element Cube Hazmat died at his post because

died at his post because they forgot to relieve him

which is why it is sometimes used to make mirror surfaces

It is a silvery-metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare-earth element"

Although several elements within the Periodic Table are dangerous

Yttrium Element Cube Hazmat died at his post becauseYttrium is a chemical element with the symbol Y and atomic number 39. It is a silvery metallic transition metal chemically similar to the lanthanides and has often been classified as a "rare earth element". Yttrium is almost always found in combination with lanthanide elements in rare earth minerals, and is never found in nature as a free element. 89 Y is the only stable isotope, and the only isotope found in the Earth's crust.