Asked by: Daniel Love, Leeds
Chewing gum sticks for the same reason most glues stick – electrostatic interactions between molecules, or Van der Waals forces. Chewing gum is so pliable, it flows into every microscopic crevice, which increases the contact area for the Van der Waals attraction. Wet chewing gum doesn’t stick to your finger because a layer of water molecules gets stuck to the gum’s surface, blocking the sticky molecules.
Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.