Demo 1: Warm Air is Less Dense than Cool Air

• 1 empty, two-liter plastic bottle
• 1 balloon
• 1 large bowl
• Hot water
• Ice

Student Activity: Spinning Snakes

• Spinning Snake Worksheet, 1 per student
• Scissors, 1 per student
• Thread
• Colored pencils, crayons, markers, etc.

Demo 2: Convection Current Model

• 2 aquariums (or very large glass jars/beakers)
• 2 small plastic bags with strong seals
• Dark-colored food coloring
• Bowl (to mix water, ice and food coloring)
• 1 long straight pin
• 1 long-handled spoon or ladle
• Water
• Ice cubes
• Hot plate/microwave/stove (optional; required only if tap water is not hot enough)
• Pan or cooking container (optional; to heat water on hot plate/microwave/stove)