Materials
โ Clear plastic or glass container (e.g., petri dish or shallow dish)
โ Water
โ Measuring cylinder
โ Pipette or dropper
โ Small objects for testing (e.g., paper clip, small leaf, or coin)
โ Ruler
โ Stopwatch (optional)
Procedure
Part A: Cohesion
1. Droplet Test:
โ Using a pipette, carefully place water droplets on the surface of the petri dish.
โ Observe how many drops you can add before the water spills over the edge.
Record the number of drops.
โ Measure the diameter of the largest droplet before it spills over using a ruler.
2. Observation:
โ Discuss how the cohesion of water molecules contributes to the droplet's ability
to hold its shape and resist spilling.
Part B: Adhesion
1. Water on Different Surfaces:
โ Place small amounts of water on different surfaces (e.g., glass, plastic, wax
paper).
โ Observe the shape of the water on each surface. Record your observations
regarding how water behaves on each material.
2. Observation:
โ Explain how adhesion affects the behavior of water on different surfaces.
Part C: Surface Tension
1. Paper Clip Float Test:
โ Fill the petri dish with water until it is nearly full.
โ Carefully place a paper clip on the surface of the water. Note whether it sinks or
floats.
โ If it sinks, try to place it back on the surface gently to see if it can float due to
surface tension.
2. Soap Effect:
