Absorbency

   2004-10-23      experiment

I thought this was going to be the most boring experiment ever. I didn’t have much time to prepare so I didn’t come up with anything more exciting than the basics. As it turned out, it was wonderful.

Preparation (for class of 20):

• 20 droppers
  
• 20 cups of water
• 20 pieces (about 1” square) of:
  
  • fabric (I used a small pices of flannel)
    
  • aluminum foil
    
  • wax paper
    
  • paper napkin

Before the class started, I laid out each of the materials on a paper towel on each students desk. I asked them all what these materials were. Unexpectedly (to me) none of them could identify the fabric or wax paper. The wax paper was not so surprising since we tend to use plastic wrap or baggies, and we got a chance to talk about a time before plastic was invented. We had a long discussion of the cloth and how its the same thing that their clothing is made from. I told them that this particular cloth is made from cotton, which is a plant and threads of cotten are woven together to make the fabric. It was neat to see them really think about these basic materials in a new way. They held them up to the light and observed how the light passes through them differently.

I realized that none of these kids had ever seen or used a dropper before. I demonstrated and then they practiced getting just one drop of water to come out at a time. They had so much fun learning how if they squeezed quickly or slowly the water would squirt out or come out in drops.

We asked them to put just three drops of water on each different material. They were excited to discover how the water stayed in round drops on the wax paper, and if you put the drops near each other they would form a single drop. We talked about how some materials ABSORB water and some materials REPELL water.

Fortuitously it was a rainy day, and the teacher asked: what else repells water? did you wear something today that kept you from getting wet? “My raincoat!” and there was a chorus of “I have a raincoat too!” They all rushed to their lockers and compared raincoats. We talked about umbrellas and boots. It was amazingly fun and wonderful to see their faces in those moments of discovery.

inspired by UTexas First Grade Lab