This metal catalyzes the Sonogashira, Suzuki, Stille, and Heck reactions, though its lifetime as a catalyst is limited because hydrochloric and sulfuric acid can both slowly dissolve it and atmospheric sulfur causes it to tarnish. Its chemistry is not explained by the octet rule since it possesses ten valence electrons; it 
This metal catalyzes the Sonogashira, Suzuki, Stille, and Heck reactions, though its lifetime as a catalyst is limited because hydrochloric and sulfuric acid can both slowly dissolve it and atmospheric sulfur causes it to tarnish. Its chemistry is not explained by the octet rule since it possesses ten valence electrons; it readily undergoes transmetallation, as it is also one of the most electronegative transition metals. Its amazing capacity for adsorption of roughly 900 times its volume of hydrogen makes it an ideal catalyst for petroleum cracking and hydrogenation. For 10 points, identify this rare silver-white metal of the platinum group named after an asteroid.
This metal catalyzes the Sonogashira, Suzuki, Stille, and Heck reactions, though its lifetime as a catalyst is limited because hydrochloric and sulfuric acid can both slowly dissolve it and atmospheric sulfur causes it to tarnish.
{p}alla{d}ium [accept element {46}]