A chemical used in school science experiments

How many answers can you give to “A chemical used in school science experiments”? OnlyClick knows 89 of them, and rewards the ones other people miss. Most people go straight for Baking soda, Hydrochloric acid or Vinegar, so those barely lift the rocket. It is a fairly short list: only 14 answers sit in the two rarest tiers, so reaching one takes real knowledge.

The odd entry you read about once tends to score far better than the classroom example. You will find it in stage 45, “Reaction Time”, of the Science mission. The first stages of every mission are free, and later stages come with the full mission.