When a crystal of potassium permanganate is placed at the bottom of water in a beaker, the water in the whole beaker turns purple on its own, even without stirring. This is an example of:

When a crystal of potassium permanganate is placed in a beaker of water, the water slowly turns blue on its own, even without stirring. Both potassium permanganate crystal and water are made up of tiny particles. On dissolving, the particles of potassium permanganate get into the spaces between the particles of water. This process is called diffusion.

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