Kid-Oriented Science Project Ideas

While digital thermometers have taken over the old glass-based mercury ones, kids can still learn an important (and visual) lesson on how temperature is determined. Among the many science project ideas for kids, creating your own homemade thermometer is an easy one to implement.

You and your child will need room temperature water, rubbing alcohol, food coloring, and a clear plastic straw, not the bendable, colored, or striped kind. You will also need a clear plastic bottle and approximately eight to eleven ounces and modeling clay.

Directions for the Project

Fill the bottle up to Â¼ of the way full with equal parts alcohol and water. Choose your favorite food coloring hue and put a few drops into the liquid solution and mix until blended. Place the clear straw in the bottle but do not allow it to touch the bottom of the bottle. Instead, using the modeling clay, seal the neck of the bottle to hold the clear straw in place.

Next, using your hands, wrap them around the bottom of the bottle where the mixture is contained. What do you see? Try placing the bottle outside in the sunshine and observe what happens. Patience may be needed as the water in the bottle warms up a bit.

Explaining the Project

The homemade thermometer project is among the easiest science project ideas because of its quick assembly time and the ability of young kids to understand how taking someone's temperature works. Remember with the old mercury thermometers the red color rose based on how high your temperature was? Your child will discover in this controlled experiment how the colored mixture inside the bottle expands as it warms up. When the water has no where else to go as it expands, it pushes up through the straw.

With hot temperatures, the water mixture may rise up through the straw and out the top. However, what happens to the colored mixture as the temperature cools off? Your child can discover this too through observation. The mixture's level in the straw goes down. This theory can easily be tested with a real old-fashioned thermometer in comparison so you and your child will know exactly how thermometers work - heat rises causing higher temperatures.