How Does Adding Soap Affect the Floating Paperclip Experiment?

What happens when a student adds a drop or two of dish soap to the water in the floating paperclip experiment?

Does the paperclip continue to float or does it sink?

Answer:

When a student adds a drop or two of dish soap to the water in the floating paperclip experiment, the paperclip will most likely sink. The addition of the soap changes the surface tension of the water, causing the paperclip to fall through the water to the base of the dish.

The floating paperclip experiment is a classic science demonstration that showcases the concept of surface tension. When a small paperclip is carefully placed on the surface of water in a glass dish, it floats due to the surface tension of water holding it up. However, when dish soap is added to the water, it disrupts the surface tension, causing the paperclip to sink.

Soap is a surfactant, which means it decreases the surface tension of water. Surfactants work by reducing the cohesive forces between water molecules at the surface, making it harder for the water to support the weight of the paperclip. As a result, the paperclip no longer floats on the surface but instead falls through the water to the bottom of the dish.

In conclusion, adding soap to the water in the floating paperclip experiment changes the surface tension of the water, causing the paperclip to sink. This simple demonstration highlights the role of surface tension in supporting objects on the surface of water and how it can be altered by the addition of surfactants like soap.