Fix a balloon over the neck of a bottle and put the bottle in hot water. Explore what will happen?
When the bottle is placed in hot water, the air particles inside the bottle gain thermal energy and move faster.
The increased movement causes the particles to spread farther apart, increasing the volume of air.
Since the bottle is sealed with a balloon, the expanding air pushes into the balloon, causing the balloon to inflate.
This demonstrates that gases expand when heated and that gas particles move faster and spread apart with increased thermal energy.
Explanation
The chapter explains that heating increases the thermal energy of particles, causing them to move more vigorously. In gases, particles already have maximum spacing and negligible interparticle attractions, so they expand readily when heated. This activity demonstrates the effect of thermal energy on gas particles.
Solution Steps
Air particles inside the bottle gain thermal energy from hot water and move faster
Particles spread farther apart, increasing the volume of air
Expanding air pushes into the balloon, causing it to inflate
Demonstrates that gases expand when heated