69. Philosopher’s wool is chemically A.Aluminium oxide B.Magnesium oxide C.Zinc oxide D.Calcium oxide
Answer: Option C Solution: The compound zinc oxide (ZnO) is called philosopher's wool. Alchemists, as part of their rituals, would burn zinc in air and collect the residue, which formed into white woolly tufts. They called it lana philosophica in Latin, meaning philosopher's wool.
