Obedient coin

This experiment illustrates how air expands when heated and contracts when cooled, affecting pressure. A coin is placed on the mouth of a bottle. When the bottle is warmed, the air inside expands, increasing the internal pressure and causing the coin to move or even jump. Conversely, cooling the bottle causes the air inside to contract, reducing the internal pressure and pulling the coin inward. This demonstrates the principles of thermal expansion and contraction of gases.

Learning Objective:

 To understand the relationship between temperature and air pressure, showcasing how heating and cooling affect gas volume and pressure, leading to observable physical effects.

Keywords:

 Air expansion, Air contraction, Thermal expansion, Gas behavior, Temperature effects, Thermodynamics