Ammonium nitrate
Ammonium nitrate is a colorless solid. It dissolves in water. It makes water cold when it dissolves. It is an oxidizing agent. When it is heated gently, it turns into water and nitrous oxide. It can detonate when heated strongly. There were several disasters where ammonium nitrate exploded. Ammonium nitrate fertilizers were banned in some places because they were used to make explosives.