Nucleation

Definition

The kinetic barrier that prevents supersaturated water from instantly forming crystals until a first stable nucleus appears.

Ions collide billions of times per second and most encounters are fleeting because thermal motion pulls them apart. Early clusters dissolve because the energetic cost of creating a new solid liquid interface outweighs the benefit of lattice formation. Only when a cluster grows beyond a critical size does the balance flip and a stable nucleus form, the first handshake after which scale formation accelerates.

Related concepts

Crystal Growth · Critical Size · Threshold Inhibition

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Part of The Blueprint of Water · 🧪 chemistry