Darwin!!
“It was reported that the student used to dip chewing gum into citric acid. Police also found another substance near the body”
Am I to understand that he made his OWN exploding chewing gum?
Kind of like “Spring Surprise” or “Crunchy Frog” (Monty Python reference for non-geeks among us)
I can’t imagine too much interesting chemistry with gum and citric acid. If he managed to confuse it with nitric acid, then a variety of unstable chemicals could be produced.