Surface Tension

What property of water allows water striders and carefully placed paper clips to stay on its surface?

• Density

• Buoyancy

• Surface tension

• Viscosity

Why do water molecules at the surface of a liquid behave differently from those in the bulk of the liquid?

• They are attracted to air molecules above them.

• They experience balanced attractive forces from all directions.

• They are only pulled downwards and sideways by other water molecules.

• They have higher kinetic energy than bulk molecules.

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What causes surface tension in a liquid?

• The repulsive forces between surface molecules.

• The attractive forces (cohesion) exerted on surface molecules by molecules below them.

• The density difference between the liquid and the air.

• The kinetic energy of the water molecules.

How does surface tension allow water striders and carefully placed paper clips to remain on the water's surface?

• It increases the density of the water, making objects float.

• It creates a stretched, elastic-like film that supports light objects.

• It reduces the weight of the objects, allowing them to float.

• It causes the objects to become buoyant.

Why do water droplets tend to form spherical shapes?

• To maximize their surface area.

• Due to the effects of gravity pulling them into a round shape.

• To minimize their surface area, which is a consequence of surface tension.

• Because water molecules are naturally spherical.