With this project, kids can explore the properties of gas and a simple chemical reaction using products commonly found around the home. Gather together a latex balloon, 1/4 cup of water, 2-liter soda bottle, straw, lemon, 1 teaspoon of baking soda, and a 20-ounce soda bottle. Stretch out the balloon, removing any kinks and open the nozzle. This will make it easier for the gas to fully inflate the balloon. Carefully, pour 1/4 of water into a clean, 2-liter soda bottle. Cut a lemon in half, squeeze the juice from both halves carefully into a separate container. Add 1 teaspoon of baking soda to the water and swish it around in the bottom of the bottle until it dissolves. Insert the straw into the bottle. With a 2-liter bottle, it may be necessary to tape it to the edge to prevent it from falling in. Quickly, add the lemon juice and stretch the balloon over the mouth of the bottle so the straw is inside the balloon. Repeat the experiment with a 20-ounce bottle. Which balloon inflates more?
A barometer is a weather instrument used to measure changes in the air pressure. Meteorologists use barometers to help predict storms and other weather conditions. A balloon is a key component to making an at-home barometer. For this experiment, you'll need a balloon, a jar, scissors, a rubber band, tape, a straw, an index card and a felt-tip marker. Cut off the nozzle of the balloon where you normally blow in air. Stretch the balloon over the mouth of a jar. This is also a great way to recycle an old jelly or peanut butter jar. Wrap a rubber band around the mouth of the jar to secure the balloon in place. Tape a straw parallel across the top of balloon. On an index card, draw three, horizontal lines about 1/2-inch apart. Label the bottom line "low," the middle line "average" and the top line "high." Tape the card vertically along the back of the jar. Adjust the straw so it sits at average. Set the jar on a flat surface. Observe how air pressure changes in the room affect the barometer.
Balloons are a wonderful power source for a simple, homemade rocket. Use this rocket project to introduce kids to the basic principles of physics including laws of motion and the effects of force. The following materials are required: fishing line, straws, balloons and tape. Sting a fishing line across the room to make a rocket track. Next, thread a drinking straw on to the fishing line. Blow up a balloon and pinch the end to keep air from escaping. Add two circles of tape to the bottom of the balloon; stick the balloon to the straw. Let go and watch it fly. Repeat making the balloon different sizes. How does the size affect the distance traveled?
Use a balloon to create a mini-hot air balloon at home. This project helps students learn about the different densities between hot air and cold air. For this project gather together empty soda bottles and balloons, and ensure access to both hot and cold water. Either 2-liter or 20-ounce-sized bottles work for this project; recycle whatever is on hand. Stretch two balloons over the mouth of two different bottles. Place one bottle in the freezer and keep the other at room temperature. Fill a large pot half full with hot water. Place the cold bottle from the freezer into the hot water. Record any observations. Repeat with the room-temperature bottle. Dump out the water and fill with cold water. Repeat. Does cold water change the outcome? Discuss out hot and cold air are used to fly a hot air balloon.