Chemical Used to Lighten, Bleach Hair
Puzzle 13 of Couples Costumes Easy Pack
Question is: Chemical Used to Lighten, Bleach Hair
and the answer is: PEROXIDE
Word Meaning:
PEROXIDE — (inorganic chemistry) A divalent radical or anion containing two oxygen atoms linked by a covalent bond; any substance containing this group yields hydrogen peroxide when treated with an acid.
Definitions from Wiktionary.