Thermal expansion of solids, liquids and gases

As the temperature of the gas increases, the kinetic energy of the gas particles increases. This causes them to move faster and collide more frequently and forcefully with the walls of the container. Since the pressure is constant, the volume must increase to compensate for the increased force, maintaining a constant pressure. Therefore, the volume of the gas increases.

The length of the metal rod increases. This is because the metal rod expands due to an increase in temperature.

A bimetallic strip is made of two different metals with different coefficients of thermal expansion. When the temperature increases, the metal with the higher coefficient expands more than the other. This difference in expansion causes the strip to bend. In a thermostat, this bending can be used to make or break an electrical contact, switching a heating or cooling system on or off. Thus regulating the temperature.

1. Expansion joints in bridges: These gaps allow the bridge structure to expand and contract with temperature changes, preventing stress and cracking.
2. Hot air ballooning: Heating the air inside the balloon causes it to expand, making it less dense than the surrounding air and providing lift.

Answer:
In gases, particles are widely spaced with weak intermolecular forces. When heated, gas particles gain kinetic energy, moving faster and further apart. The weak forces allow for greater expansion. In solids, particles are closely packed with strong forces. Increased kinetic energy mainly increases vibration, with limited expansion against strong forces.

Answer:
Solids < Liquids < Gases