Make Your Own Thermometer

You have been studying how to measure matter. The activity below will help you better understand how thermometers work.




Ask an adult to help you pour some water into the soft-drink bottle. Add a few drops of food coloring. Stick the straw into the bottle and mold the clay around the straw and around the top of the bottle. The straw should be 1 centimeter above the bottom of the bottle. The water in the bottle will rise a bit. Let the water and bottle sit at room temperature until the water level stops changing. Mark the level of the water on the straw with a marker. Now check the temperature of the room with the thermometer. Using the other marker, mark that temperature on the straw near the water level mark. Fill the pan with warm water and place the bottle in the pan. Wait for the water to stop rising, and then take the temperature of the water in the pan. Label that reading as the top reading on your straw and mark it. You have two temperature readings, one high and one low. Make equally spaced marks on the straw between the two readings. You have made a thermometer.


What happened to the water when it was warmed? Why do you think the water moved up the straw?