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Why does liquid mercury form rounded droplets on glass instead of sticking to it?

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A periodic table element box for mercury shows its symbol Hg, atomic number 80, atomic weight 200.592, electron configuration, and name. Icons indicate mercury is a transition metal, liquid at room temperature, has a rhombohedral crystal structure, and is weakly basic. — mercury Properties of mercury.

Liquid mercury forms rounded droplets on glass because its internal cohesion is significantly stronger than the adhesion between the mercury and the glass surface.1

In physics, cohesion refers to the attractive forces between molecules of the same substance, while adhesion refers to the forces between molecules of different substances. Because mercury possesses a very high surface tension, its atoms are strongly attracted to one another, causing the liquid to minimize its surface area by pulling itself into a spherical shape. Unlike water, which wets glass because the adhesive force between water and glass is stronger than the water's internal cohesive force, mercury’s cohesive forces dominate, preventing it from spreading out or sticking to the glass.12