Hot vs Cold: Discovery at Home

What you need:

  • Plastic bottle.
  • Balloon.
  • Two containers.
  • Ice water.
  • Hot water from faucet.

Directions:

  1. Attach the balloon to the open part of the empty plastic bottle so it traps the air inside the bottle and balloon.
  2. Fill one container about half full with ice water.
  3. Fill the other container about half full with hot water. (Not boiling water, just hot water from the faucet).
  4. Make a hypothesis about the experiment. What do you think will happen?
  5. With the balloon attached, place the bottom of the bottle in the ice water, hold the bottle so it is partially under water, and watch the balloon.
  6. Make observations. What happens?
  7. With the balloon attached, place the bottom of the bottle in the hot water, hold the bottle so it is partially under water, and watch the balloon.
  8. Make observations. What happens?
  9. Go back and forth between the ice water and hot water a few times.
  10. Make observations. What happens?

Ways to Expand the Activity:

  • Do the same experiment with different sized bottles. Does anything change?
  • Put different colors of food coloring in your hot and cold water and mix them together. How do they mix?

What Kids Learn:

  • Language. When children experience new things like a science experiment, they are able to practice their language skills, express ideas and opinions, and use descriptive words.
  • Cause and effect. When you put the bottle into the cold water, the balloon contracts. When you put the bottle into the hot water, the balloon inflates.
  • Concentration. Experiments where children need to watch for results helps improve their concentration.
  • Basics of thermodynamics. When children are able to explore the basics of science or a specific field in science in a hands-on manner, they are able to relate the new information being learned to past experience to help develop knowledge on that subject. This experiment teaches a key principle of thermodynamics: when molecules heat up, they move around quickly, and take up more space.

Vocabulary:

  • Thermodynamics. A branch of science that deals with heat relating to other forms of energy.