Metal Named After a Dwarf Planet
Puzzle 19 of Periodic Table Medium Pack
Question is: Metal Named After a Dwarf Planet
and the answer is: PLUTONIUM
Word Meaning:
PLUTONIUM — The transuranic chemical element with atomic number 94 and symbol Pu: a silvery-gray fissile radioactive actinide metal that tarnishes when exposed to air.
Definitions from Wiktionary.