Science info on Instagram: "The Pharaoh’s Serpent is a classic chemistry demonstration illustrating thermal decomposition and gas expansion. In the historical version, mercury(II) thiocyanate is ignited. When heated, it decomposes exothermically, producing a carbon-rich solid and releasing gases. The rapid gas expansion forces the solid residue to grow outward, forming a long, porous, snake-like structure. Today, the same physical mechanism can be demonstrated safely using a mixture of sugar and