Explodium

Explodium is a very, very, very explosive element, found in very small quantities in the UnWorld. When provoked in any way, Explodium will quickly and violently explode. The element Magnetium is the only known element that can neutralize the explosive effect, meaning all Explodium must be transported in Magnetium. A reaction that created massive amounts of Explodium is blamed for the destruction of the planet Radon.