Zeroth law of thermodynamics

Definition

The zeroth law of thermodynamics states that if two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other. This law forms the basis for the concept of temperature.

5 Must Know Facts For Your Next Test

1. The zeroth law allows for the definition of temperature as a fundamental and measurable property.
2. It implies that temperature is a transitive property among thermodynamic systems.
3. Thermal equilibrium means no net exchange of heat between systems.
4. The zeroth law is essential for the construction and calibration of thermometers.
5. It precedes the first and second laws of thermodynamics logically, thus named 'zeroth'.

Review Questions

• What does it mean for two systems to be in thermal equilibrium?
• How does the zeroth law enable the use of thermometers?
• Why is it called the 'zeroth' law instead of being included after the first or second laws?

Related terms

First Law of Thermodynamics: States that energy cannot be created or destroyed, only transferred or transformed; also known as the conservation of energy.

Thermal Equilibrium: A condition where two systems in contact with each other exchange no net heat energy.

Temperature: A measure of the average kinetic energy of particles in a substance, determining its thermal state.