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AMA Junior Camp V3 Project 3

a visual of air, fluid, and density, water bottle and balloon experiment

Supplies Needed:

  • Empty Plastic Bottle: 8-16.9 oz
  • 1 oz Vinegar
  • 1 tsp Baking Soda (7 grams)
  • Funnel
  • Balloon
  • Bowl of Very Cold Water
  • Bowl of Very Hot Water (Adult Supervision Required)


  • Discover the world of molecules and their role in gases like air.
  • Explore the behavior of fluids.
  • Understand density and its relationship with molecules and fluids.
  • Learn how density can be altered by changing other factors.

Instructions, Part 1: The Reaction Begins!

  1. Pour the vinegar into the bottle using the funnel.
  2. Stretch the balloon over the funnel’s narrow end, with the wide end facing up.
  3. Securely hold the balloon and funnel, then pour the baking soda into the funnel.
  4. Remove the funnel, keeping the baking soda inside the balloon.
  5. Attach the balloon to the bottle’s opening, ensuring a tight seal.
  6. Tip the balloon to release the baking soda into the bottle.

Background Info, Part 1: A Gas is Born! When vinegar meets baking soda, they create carbon dioxide (CO2) gas. The balloon inflates as this gas seeks more space than what’s available in the bottle, filling up the balloon too. Gases like CO2 and air are fluids that occupy space, crucial for understanding flight dynamics.

Instructions, Part 2: The Density Dance!

  1. Seal an empty balloon over the bottle’s opening.
  2. Submerge in cold water—no change! The air molecules huddle closer due to the chill.
  3. Now dip in hot water—watch it inflate! The molecules spread out, taking up more room because of the warmth.
  4. Back in cold water—deflate slightly! The molecules condense again as they cool down.

Background Info, Part 2: Density in Action! The air inside remains constant; it’s all about density changes. Cold air is denser as molecules are snugger together. Warm air is less dense with molecules more spread out.

AMA Jr. Camp project #3: Air, Fluids, & Density

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