Hard Metal Used in Ball-Point Pen Tips, Symbol Os
Puzzle 11 of Periodic Table Medium Pack
Question is: Hard Metal Used in Ball-Point Pen Tips, Symbol Os
and the answer is: OSMIUM
Word Meaning:
OSMIUM — A chemical element (symbol Os) with atomic number 76: a hard, brittle, heavy, bluish-white transition metal found as a trace element in alloys, mostly in platinum ores.
Definitions from Wiktionary.