Sunday, April 6, 2014

Surface Tension Fun

 This is a great experiment for kids - easy, nothing fancy to purchase and has the WOW factor that makes science experiments so much fun! All you need is a bowl of water, pepper or glitter and dish detergent. Sprinkle the glitter over the surface of the water. The glitter will float due to the water's surface tension. Dip your finger into dish detergent, then put it into the middle of the glitter and WHOOSH!!!! the glitter goes flying to the sides of the bowl creating a huge clear area in the center! It happens really fast, many screams! We did this experiment 3 times yesterday & changed up some variables.
First we used pepper:

Then we used glitter to see if the same thing will happen (yes!).
Then we added TONS of glitter to see if the same results occur (no!).

My students had to answer these questions along the way:
-Why is the glitter floating and not sinking? (Water is made of molecules that "hold hands" - these molecules create something called surface tension - things will float on water as long as that surface tension is not broken.)
-Why does the glitter  run to the sides of the bowl when we put a soapy finger in the middle? (Soap breaks the surface tension of water. The water molecules run away from the soap, carrying the glitter with them!)
-Why won't this experiment work if we add too much glitter? (There is no where for the water & glitter to move to, we created a glitter traffic jam!)
-What are some other ways we can change up the experiment? (See if hot water works, seltzer, oregano, what else can we think of to experiment with?)
My 2/1/13 blog post on The Scientific Method has a freebie that you can use with this experiment.

Have fun!

1 comment :

  1. I love how you explain the complicated science theories is such an understandable way to the kids (and me! lol!). I'm getting so many great ideas from you site that I want to try with my daughter!

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