What Are the Variables in “Float a Needle” from “Science Wizardry for Kids” by Margaret Kenda. “Floating a Needle” is an exploratory investigation about surface tension. Surface tension is the property of liquids in which the exposed surface acts as if a thin skin has been pulled across it. This property is due […]
Cohesion: Surface Tension
What is Cohesion and How does it Relate to Surface Tension Cohesion is the attraction that like- molecules have for each other. Water molecules have an attraction for each other. This attraction is called cohesion. Surface Tension Surface tension is the skin-like surface of a liquid due to the cohesive forces between the liquid […]
Soap Bubbles
Question: Why doesn’t water form bubbles? Answer: Cohesion is the force between molecules that are alike, such as between water molecules. The cohesion between water molecules too strong to allow the water to form bubbles. The bubbles shown in the photo are made with a solution of soap and water. The soap reduces the force […]
Surface Tension
Question: What is the trick behind floating a paper clip on water? Answer: There is no trick. The diagram shows the paper clip on a small piece of paper. I used a piece of paper towel. The paper helps to position the paper clip so that is sits flat on the water. The pencil in […]