How do you make a burnt coin silver again? 🪙 In this science experiment @Alex Dainis 🧬🔬 demonstrates why soot from a flame is hydrophobic! Soot is mostly made up of small carbon and hydrocarbon particles that repel water making it hydrophobic. When you place the soot covered coin under water a small layer of air forms around it. This creates an air/water interface which causes the light to refract, making the coin look clean! Once you take the coin back out, the sooty appearance will return.