Which object has less thermal energy?
a 120-gram bottle of water at a temperature of 10°C a 120-gram bottle of water at a temperature of 20°C
The objects are identical except for their temperatures.
All solids, liquids, and gases are made of matter. Matter is made up of tiny particles that are always moving. The energy from the motion of these particles is called thermal energy.
Temperature measures how hot or cold matter is. If the particles in matter slow down, the temperature goes down. The matter now has both less thermal energy and a lower temperature.
The two bottles of water have the same mass but different temperatures. Since the 10°C bottle of water is colder than the 20°C bottle of water, it has less thermal energy.