Thermal energy

Definition

Thermal energy is the internal energy in a system due to its temperature, arising from the random motion of its particles. It is a form of kinetic energy resulting from the microscopic movement of atoms and molecules.

5 Must Know Facts For Your Next Test

1. Thermal energy increases with an increase in temperature, as particle motion becomes more vigorous.
2. It is directly proportional to the number of particles in a substance; more particles mean more thermal energy at a given temperature.
3. In thermodynamics, thermal energy transfer between systems can occur through conduction, convection, or radiation.
4. The specific heat capacity of a material determines how much thermal energy is required to change its temperature by one degree Celsius.
5. During phase changes (e.g., melting or boiling), thermal energy is used to break intermolecular bonds rather than increase temperature.

Review Questions

• What happens to the thermal energy of a substance as its temperature increases?
• How does the specific heat capacity affect the amount of thermal energy needed for a temperature change?
• What are the three methods through which thermal energy can be transferred?

Related terms

Kinetic Energy:

The energy possessed by an object due to its motion. It is calculated using $KE = \frac{1}{2}mv^2$ where $m$ is mass and $v$ is velocity.

Potential Energy:

The stored energy in an object due to its position or configuration. Examples include gravitational potential energy and elastic potential energy.

Specific Heat Capacity: $c$, defined as the amount of heat required to raise the temperature of one kilogram of a substance by one degree Celsius.