What will you need:

1. Tap water
2. Rubbing Alcohol
3. Clear narrow necked plastic bottle (water bottle will work just fine)
4. Food coloring
5. Clear drinking straw
6. Modeling clay or play-doh

Directions:

1. Pour equal parts of tap water and rubbing alcohol into the bottle, filling about 1/8 to a ¼ of the bottle.
2. Add food coloring to the water and alcohol mixture and mix well
3. Put the straw in the bottle, but don’t let it touch the bottom.
4. Use the modeling clay/ play-doh to seal the top of the bottle so the straw stays in place.
5. Hold hands on the bottle and see what happens to the mixture.
6. When done with experiment, make sure bottle is disposed of and not reused!

Cool science explained:
The mixture in the bottle will expand when it gets warm, which means it will no longer fit in the bottom of the bottle and must move up through the straw. If the bottle were to get really hot, the liquid would have to come through the top of the straw. Put the bottle in the sun & shade to see the difference (feel free to mark lines with sharpie).

*Note: this thermometer will teach a little bit about science and temperature, but you won’t be able to record an exact temperature unless you buy a real thermometer.

-Lauren D, creative intern with LLD by day & babysitter & older sister by night.