Molecular forces determine liquid properties

Steps:

• Liquids maintain fixed volume due to strong intermolecular forces keeping molecules close together.
• Liquids lack fixed shape because molecules can slide past each other freely.
• Evaluate options: large forces ensure cohesion for volume, while free movement allows shape change.
• Option A matches both fixed volume (large forces) and no fixed shape (free movement).

Why A is correct:

• In liquids, strong intermolecular attractions (like van der Waals forces) limit distance between molecules for fixed volume, but allow sliding for adaptability to container shape.

Why the others are wrong:

• B: Large forces with fixed positions describe solids, not liquids.
• C: Small forces fail to maintain fixed volume, leading to gas-like behavior.
• D: Small forces with fixed positions contradict liquid fluidity and cohesion.

Final answer: A