Thermal Expansion

• What is thermal expansion?

  Thermal expansion is the tendency of matter to expand on heating.
• In which states of matter can thermal expansion be observed?

  Thermal expansion can be observed in solids, liquids, and gases.
• How does thermal expansion apply to a thermometer?

  In a thermometer, mercury expands when heated, causing its level to rise.
• What is typically used as the liquid in a thermometer?

  Mercury is typically used as the liquid in a thermometer.
• Why does gasoline come out of a tank when it is filled to the brim and heated?

  Gasoline expands on heating, and if there is no space left in the tank, it forces gasoline to come out.
• What happens to steel rails when they are heated?

  Steel rails expand on heating and contract on cooling.
• Why are small gaps left between railway tracks?

  Small gaps are left to provide space for the expansion of the rails during heating.
• What can happen if railway tracks are joined without leaving space for expansion?

  If railway tracks are joined without space, they can bend due to thermal expansion, causing accidents.
• What are the consequences of thermal expansion in everyday objects?

  • Thermometers: Mercury rises with heat.
  • Gasoline tanks: Gasoline spills when heated.
  • Railway tracks: Gaps prevent bending and accidents.
• Thermal expansion can be used to measure temperature changes, as it causes an object's dimensions to expand or contract with temperature changes.