Multiple choice general knowledge

When cutting onions, what chemical is released that makes your eyes water?

  1. Sulphur

  2. Cyanide

  3. Potassium

  4. Calcium

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

The answer refers to syn-propanethial-S-oxide, a volatile sulfur compound released when onion cells are damaged. It reacts with eye moisture to form mild sulfuric acid, causing tearing.