málmjónið
Málmjónið, often translated as metallic hydrogen, is a theoretical state of matter that is predicted to exist under extremely high pressures. At these immense pressures, typically found in the cores of gas giant planets like Jupiter and Saturn, the electrons in hydrogen atoms are thought to become delocalized, similar to electrons in metals. This would cause hydrogen to behave like a metal, exhibiting electrical conductivity.
The concept of metallic hydrogen was first proposed by physicist Eugene Wigner and metallurgist Frederick Seitz
Despite extensive theoretical work, metallic hydrogen has not been definitively created or observed in a laboratory