Cohesion (or how we just love using eye droppers!)

     Yesterday, we started using this book:

  

It is has 24 experiments in them.  We did the first one yesterday.  We compared the size and shape of drops of different liquids, then ordered them according to their relative cohesive strength. 

We tested soapy water, canola oil, tap water and rubbing alcohol.  (My kids really wanted me to put "poison" on the container...so funny!)

They loved using eye droppers!

We lined up one drop from all the liquids to compare them.

After we compared the droplets on the wax paper, we measured 50 drops of each liquid in a graduated cylinder.  (My chemistry days are coming back to me!!)

34, 35, 36....

Getting eye-level to get the exact measurement.

All put together in their science notebook...

(Oh, by the way: Tap water had the greatest cohesive strength.  It was the tallest droplet, and took up the most volume in the graduated cylinder.)