demonstrations:liquid_nitrogen_freezing_bouncy_ball

Freezing a Bouncy Ball in Liquid Nitrogen

Materials: ★★★ Requires materials not commonly found in school laboratories
Difficulty: ★★☆ Can be done by science teachers
Safety: ★★★ Only to be attempted with adequate safety procedures and trained staff

Categories: Materials, Liquid Nitrogen

Alternative titles: Unbouncy Ball Experiment

Summary

A bouncy ball submerged in liquid nitrogen loses its elasticity because the extreme cold freezes its rubber molecules into a rigid, brittle structure. As a result, the ball cannot compress and rebound, making it unable to bounce until it warms up again.

Procedure

  1. Place a bouncy ball into a container of liquid nitrogen using tongs.
  2. Leave the ball submerged for several minutes until thoroughly cooled.
  3. Wearing safety glasses and gloves, remove the frozen ball.
  4. Drop the ball onto a hard surface and observe its reduced bounce (or shattering).
  5. Allow the ball to return to room temperature and test again to see its bounciness restored.

Can you FREEZE a bouncy ball? | liquid nitrogen experiment - Wonderlab+:


Don't Put Bouncy Ball in Liquid Nitrogen - Mr. Ax: The BackBencher Experiment:


Variations

  • Compare different types of balls (rubber superballs, tennis balls, racquetballs).
  • Drop the frozen ball from different heights to see if it shatters or simply thuds.
  • Test the bounce height of the ball at room temperature versus after freezing.
  • Use slow-motion video to capture the difference in impact behavior.

Safety Precautions

  • Safety glasses required.
  • Wear cryogenic gloves when handling liquid nitrogen and the frozen ball.
  • Handle the ball with tongs immediately after freezing — it may be brittle and sharp if it breaks.
  • Only perform in a well-ventilated area to prevent nitrogen buildup.
  • Do not attempt this with balls containing liquids or pressurized gas (they may burst).

Questions to Consider

  • Why does rubber normally allow a ball to bounce?
  • How does liquid nitrogen change the molecular structure of rubber?
  • Why does the frozen ball sometimes shatter like glass?
  • What type of energy conversion allows a normal ball to bounce?
  • How does warming the ball restore its elasticity?
  • What other everyday materials might behave similarly when frozen with liquid nitrogen?