Thermal Energy Basics
This is the total energy of all the particles in a substance.
Thermal energy
Thermal energy naturally moves from an object with a higher temperature to one with a ___ temperature.
Lower
When thermal energy is added to matter, the particles generally move ___.
Faster
A metal spoon becomes hot after sitting in hot soup. This is an example of ___.
Conduction
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A 70°C metal block is placed in contact with a 20°C metal block. After several minutes, both blocks are 45°C. What happened to the thermal energy, and why did the blocks eventually reach the same temperature?
Thermal energy transferred from the 70°C block to the 20°C block. The transfer continued until the blocks reached thermal equilibrium at the same temperature.
This measurement tells us how hot or cold something is.
Temperature
The transfer of thermal energy through direct contact between particles is called ___.
Conduction
When a substance is heated, its particles generally move faster, causing its temperature to ___.
Increase
A student touches a cold metal desk. Thermal energy moves from the student's warmer hand to the ___.
The desk
This type of energy is related to the motion of particles within matter.
Thermal energy
The transfer of thermal energy through the movement of a fluid is called ___.
Convection
During melting, a solid changes into this state of matter.
Liquid
Warm air rises while cooler air sinks. This is an example of ___.
Convection
Two objects at different temperatures are placed in contact. Thermal energy transfers until they reach this condition.
Thermal equilibrium / same temperature
Energy from the Sun reaches Earth through this type of thermal energy transfer.
Radiation
During boiling, a liquid changes into this state of matter.
Gas
A student puts an ice cube in a glass of warm water. Explain what happens to the thermal energy.
Thermal energy moves from the warmer water to the colder ice until the temperatures move toward equilibrium.
Explain the difference between temperature and thermal energy.
Temperature measures the average kinetic energy of particles, while thermal energy is the total energy associated with the particles of a substance.
Name and describe all three methods of thermal energy transfer.
Explain how adding or removing thermal energy can cause matter to change state.
Adding thermal energy can increase particle motion and cause changes such as melting, evaporation, or boiling. Removing thermal energy can slow particles and cause condensation, freezing, or deposition.
A black metal car and a white metal car sit in direct sunlight. Explain how radiation transfers thermal energy to the cars and how this could affect their temperatures.
Radiation from the Sun transfers thermal energy to both cars. The surfaces absorb radiant energy, increasing the thermal energy and temperature of the cars. The amount absorbed can depend on the surface properties, including color.