LIQUIDS IN SUSPENSION EXPERIMENTS

LIQUIDS IN SUSPENSION—LAVA LAMP

This week we started by my asking if anyone knew what I meant by liquids in suspension.  Anaka who is in 4^th grade explained it was liquids in a bottle that didn’t mix like oil and water. She was right and we were going to prove it as we did our experiments.

1.      We started our by making a lava lamp.  We used any bottles we could find.  Some kids brought glass jars and others used water or soda bottles. All bottles or jars needed lids. Each child  filled the bottle with ¼  water and then filled it to over ¾ with oil.  Add a few drops of food coloring.  Do not mix the colors as they will blend together.  The first observation was that the food coloring dropped down to the water and did not mix with the oil.  If the bottle was shaken the food coloring would rise up with the oil like lava and then drop down.  We added ½ of an alka seltza pill to the bottle and all were excited about what happened.  It behaved just like a lava lamp that you buy in the store.  When the Alka Seltzer mixed with the water it dissolved and the food coloring and water drops  exploded up in the bottle. I asked why?  The kids had no idea. Alka Seltzer is just like baking soda and when it hits the water carbon dioxide gas forms pushing the water and food color up. The “lava” will stop after the Alka Seltzer dissolves but more can be dropped in.

             LIQUIDS IN SUSPENSION--PAINTING WITH MILK





      Our next project was to see what happens with whole milk, food coloring, and Dawn dish soap. We put enough milk to cover our tray. I used allergy needle trays, but any tray or saucer with sides will do. Next drop little drops of food coloring into the milk. The food coloring and the milk do not mix.  Take a Q-tip, dip it into the dish soap and put it into a drop of food coloring in the tray and watch it form patterns. This can be done over and over again to form new patterns. Now take a piece of paper, lay it on the designs in the tray and make it a print. Why didn’t the milk and food coloring mix?  The answer is that whole milk is a fat like oil and it stays in suspension until you add soap.

LIQUIDS IN SUSPENSION--OIL AND WATER

3.      Try the same experiment with oil, water, and  food coloring . T here is a famous painter who makes pictures out of this mix.Put only enough 

    oil to cover bottom of the tray.The colors will

     make a darker print.

4.      Just to try something else we added a small piece of Alka Seltzer to each tray and watched the carbon dioxide gas form bubbles and mix the colors.

Not only did the kids have fun doing these experiments but so did the parents who were here.  Many paper prints were made from the beautiful flowing patterns.

A special note—this can become very messy so cover all tables with plastic and newspapers to absorb the liquid. I had two of the kids get so into the project and the moving colors, they used their fingers to add soap to the colors. They were covered in messy soap paint.  Good thing it was soap so it washed out easily.