Concept:Surface tension arises from intermolecular forces between liquid molecules.
Explanation:When mercury is spilled on glass, its molecules pull more strongly toward one another than toward the glass surface.
This means the cohesive force between mercury molecules is greater than the adhesive force between mercury and glass molecules.
As a result, the mercury surface contracts to reduce its surface area.
The shape that has the least surface area for a given volume is a sphere, so small drops become ball-like.
Therefore, the ball-like shape is due to stronger cohesion inside the mercury than adhesion to the glass.
Answer:B. The cohesive force between its molecules is greater than the adhesive force between mercury and glass molecules.