What do you need to make a simple hot air balloon?

• A plastic bag and a hair dryer

• A paper bag and a heater

• A metal can and a candle

• A balloon and a fan

Why does the air inside the plastic bag become lighter when heated?

• The bag becomes smaller

• The air becomes denser

• The molecules become heavier

• The molecules move faster and get further apart

What is dry ice made of?

• Frozen carbon dioxide

• Frozen water

• Frozen oxygen

• Frozen nitrogen

What material did Phil and Michaela use to make a lighter hot air balloon?

• Dry cleaning bags and science tape

• Metal sheets and glue

• Wooden sticks and string

• Plastic bottles and rubber bands

What is blubber and why is it important?

• A special kind of water

• A layer of fat that protects from the cold

• A type of plant

• A type of ice cream