Question

A drop of oil placed on the surface of water spreads out.But a drop of water place on oil contracts to a spherical shape.Why?

Answer 1

When a drop of oil is placed on the surface of water spread out but a drop of water placed on oil contact to spherical shape because of the following reason this is because water is more denser than the oil so this leads to the fruit of oil on water

Answer 2

A drop of oil placed on the surface of water spreads but the same drop of water on oil contracts, because there are two forces acting here namely - cohesive force and adhesive force.

• The molecules of oil have cohesive force between them whereas the molecules of water have adhesive forces with molecules of oil. The cohesive force of oil is molecules are less compared to adhesive forces of water, therefore the drop of oil spreads out and the drop of water is retained as it is.
• Adhesive forces: These are the attractive forces between molecules of different types
• Cohesive forces: These are the attractive forces between molecules of the same type.