Multiple choice

Which of the following is known as philosopher wool?

  1. Clagon

  2. Zinc oxide

  3. Nitrolium

  4. None of the above

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Zinc oxide is historically known as 'philosopher's wool' or 'nix alba' because when it forms as a white, wool-like precipitate during the burning of zinc, it resembles wool. The other options appear to be made-up or misspelled terms. This historical name comes from alchemical traditions.