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 principle allows for the definition of temperature.

5 Must Know Facts For Your Next Test

1. The zeroth law establishes the concept of temperature as a fundamental and measurable property.
2. It forms the basis for the construction of thermometers.
3. Thermal equilibrium means no net heat flow between systems.
4. The zeroth law is crucial for defining what it means for two bodies to have the same temperature.
5. It enables the use of empirical temperature scales, like Celsius and Fahrenheit.

Review Questions

• What does the zeroth law of thermodynamics state?
• Why is the zeroth law important for defining temperature?
• How does the zeroth law facilitate the use of thermometers?

Related terms

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.

Thermometer:

An instrument used to measure temperature based on physical properties that change with temperature.