Water Permeability is a physical characteristic of a material which describes the material’s ability to be wet by water. In other words, the material absorbs water.
Water Impermeability is a physical characteristic of a material which describes the material’s inability to be wet by water. In other words, the material is water resistant.
Primary Research:
Exploratory Investigation
1. Purpose: To identify a positive test for materials that are impermeable to water.
Investigation:
Using an eye dropper or a straw dropper, place one or two single drops of water on a piece of wax paper.
The water drops will stand on the paper. The standing water drop is a positive test for the material being impermeable to water.
2. Purpose: To identify a negative test for materials that are impermeability to water.
Investigation
Use the same procedure of releasing drops of water on different materials, such as newspaper, construction paper,a glossy page from a magazine, and a paper towel.
In the diagram below, the green construction paper has a darker green spot. This is the result of the water drops being absorbed by the paper. If a material is wet by water (able to absorb water) the material is permeable to water.
Science Challenge
Now that you know how to test materials for being impermeable to water, use this knowledge to design a science fair project.
Example Science Fair Project Questions:
1. If a drop of water is placed on a surface, what effect would the texture of the surface have on the impermeability of the surface?
2. If a drop of water is placed on a surface, what effect would the type of water have on the surface’s impermeability to the water?
3. If a drop of a water solution is placed on a surface, what effect would the solute have on the impermeability of the surface to water?
4. If a drop of a water solution is placed on a surface, what effect would the concentration of the solution have on the impermeability of the surface material to water.
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