Science Fun With Soda Bottles

Today the kids were milling around, and I knew that if I didn't act fast, they would pull the dreaded "Mom, I'm bored!" whine.  I knew I had to find something quick and engaging, something that would spark their brains for the day.  After a quick search through some of my home schooling science books, I set up our patio table for some entertaining science activities starring something we never seem to run out of:  2 liter soda bottles!  (We drink a lot of soda)

Behold, the outdoor lab!

Our first 'experiment' was actually more of a craft, as we started by making a pair of homemade lava lamps.

First, we used a funnel to put a good amount of vegetable oil into a bottle.  I just had them eyeball it to about 1/3 of the bottle.

Next, I had them use the funnel to add water until the bottle was about 2/3 of the way full.  They added a few drops of food coloring, and waited until the oil and water settled into their separate layers. 

Finally, we added about half of an Alka-Seltzer tablet and watched the magic commence!


The next activity we did was a super simple experiment with air pressure.  All you need for this experiment is a soda bottle, a regular sized balloon, and a push pin.

First, we took the balloon and put it inside the bottle, with the end you blow up pulled on to the mouth of the soda bottle.  Then the kids took turns blowing up the balloon inside the bottle.

When that didn't work out very easily, we talked about the air inside the bottle, and how they could only blow the balloon up a little because the air inside the bottle was taking up space.  Then I took the push pin and poked a few holes along the bottom of the bottle and had the kids try again.

This time, both kids had a much easier time blowing up the balloon inside a bottle.  When I asked them why, Dirty D jumped right up and explained that when he blew up the balloon inside the bottle the second time, the balloon pushed the air that had been inside the bottle out through the holes in the bottom that I had put in with the push pin.  What a smart little scientist! :)

Our last experiment of the morning was an awesome idea I've seen several times on the internet, and it just looked so cool that I had been eager to try it out!  It's called elephant toothpaste, and it really did live up to my excitement!

Most of the descriptions I found for this experiment asked for a much smaller (around the 16 oz size) bottle, but I didn't have that, so I just decided to double up on the ingredients.  For elephant toothpaste you need dish soap, yeast, warm water, and hydrogen peroxide.  And of course, that soda bottle!  I also set my bottle up on a cookie sheet to make clean up go a little faster.

First thing you need to do is mix the yeast into the warm water.  We used 2 teaspoons of yeast to 4 tablespoons of warm water.  You stir it together for a moment and then set it aside for a few minutes while you set up the rest of the activity.

Meanwhile, use a funnel and pour a cup of hydrogen peroxide into the bottle.  Add a good squirt of dish soap and a couple drops of food coloring (optional).

Then, you use your funnel and pour the yeast/water mixture into the bottle and watch!

The foam did take a few minutes to reach the overflow point, but it was totally cool to watch!  The foamy bubbles just keep rising and rising like a snake and overflowed out onto the pan.  It really did look like toothpaste appropriate for a big ole elephant!

After having a ton of fun with some morning science play, the kids brains were sparked and they suddenly had all kinds of ideas for things to do!  (Don't you just love how that works out?)  Here's where I linked up!

http://www.icanteachmychild.com/