This activity is an exploration into the differences and similarities between the air we breathe and helium gas. Students can experiment with balloons filled with helium and air and discuss their discoveries and ideas.

• What are the differences and similarities between a balloon filled with helium and a balloon filled with air?

  Ask your students to compare the balloons and discuss how they are different and similar. Students can draw pictures explaining how they think helium balloons fly.

• How does the temperature of a balloon affect how much it can lift?

  This is the first step in exploring the relationship between temperature and density of a gas.

This activity is an exploration of the effect of temperature on gases. Students can examine how hot and cold temperatures change the properties of gases, and learn that hot-air is less dense than cold air.

• How does the volume of air change when heated?

  Your students can experiment with different ways of changing the temperature of the balloons, either cooling or heating them. Encourage your students to come up with their own ways of measuring the difference in volume. Alternative and inventive ways of measuring should be encouraged.

  Encourage group discussions.

• With the coffee can on the burner, can students feel the hot air rising from the burner? With the top opening covered with a wire screen, can students float tissue paper above the can?

  Because of the use of a hot plate, this activity is for older students. Ask them what makes the hot air rise out of the coffee can. They can change the temperature of the burner and check if it changes the force of the hot air.

• How can you tell which way the wind is going?

  Students can passively watch the skies or throw objects into the air and watch what happens. From these observations you can help facilitate their understanding that the wind is a directional force and that it can be measured.

• Which way are the clouds going?

  If your students watch clouds moving in the sky, can they see some clouds moving in different directions or at different speeds?

• Inflating the balloon

  Ask your students what is happening. Encourage discussion about how the hot air is blown into the balloon and how the hot air is kept inside the balloon.

• Lifting off

  Students can discuss how the balloon lifts off the ground.

• Rising above the ground

  Ask them how the pilots stop the balloon from rising.

• Heating the air

• Landing the balloon

Some students may have an interest in the history of balloon flight. This may be an excellent way to introduce the science discoveries involved in balloon flight.