Float-the weekly Unplugged Project

This weeks Unplugged Project was float. Because of this theme it was all about science this week. I found several activities that I wanted to do with the kids so we did a different experiment on three different days last week.

The first activity was a sinking and floating experiment. We had everything on hand for this. We needed:

3 parts water

1 part vinegar

baking soda

food coloring

little items to experiment with, we used raisins, rice, popcorn, gummies,and cashews

First we mxed the water and vinegar and then SLOWLY added a teaspoon of baking soda. (Have a towel ready at this point) We watched the fun chemical reaction, as an acid mixed with a base, forming carbon dioxide, which was given off as a gas.
Wonderful carbon dioxide.
We added a little food coloring at this point to see how active the molecules are, the coloring immediatly dispersed throughout the water.
We then added another teaspoon of baking soda--SLOWLY.

The kids then began adding the small items into the water to see what might happen.

In a short while carbon dioxide began to form on the items we added. As the gas built up on the popcorn it was able to lift the popcorn up from the bottom of the jar and to the surface, when it reached the surface of the water, the gas was released into the air and the popcorn fell again to the bottom of the jar.

Raisin worked, rice seemed to dance around, the gummies were too heavy to be lifted to the surface, little pieces of apple floated on top of our mixture, and the most active item we added were cashew nuts.

As the floating and sinking slowed down, we added more baking soda. This kept us busy watching for two hours, that is how long the "show" went on. This was a great experiment we will defininately do again.

The next two floating experiments I found at this website.

This experiment was "how to float an egg in water.

We needed:

an uncooked egg

water

salt

a wide mouth jar

Above you can see our egg, which sunk in 240 ml. of regular water.

We then removed the egg from the water and to the water we added 10 spoonfuls of salt.

We stirred

and stirred.

And then TADA!! we put our egg back in the water and it floated on the surface.

We learned that this happened because the water is now more dense than the egg, causing it to float. This also led to internet exploration of the Great Salt Lake.

After learning about density with the egg experiment, we investigated the densities of other liquids.

In the jar above we have from the bottom up:

corn syrup

water (with food coloring added)

oil

The corn syrup, being the most dense in on the bottom. Water is next and oil is the least dense and floated on top of the water. We then added small items to see what we could get to float on the different layers. A little screw fell through all layers and laid on the bottom of our jar. A raisin fell through the oil and water, but floated on the corn syrup. Popcorn also floated on the corn syrup.

It was hard, but we finally found an item that would fall through the oil and float on the water. A little lego floated on the water. You can see it on the left side of the jar in the picture above. The lego man, however, floated on the oil. So we successfully found something to float on every layer of our jar.

Make sure to check out everyones Unplugged activities this week.

The theme for next week’s project will be:
Wrinkle