Which object has less thermal energy?
a tray of lasagna at a temperature of 20°C a tray of lasagna at a temperature of 10°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 trays of lasagna have the same mass but different temperatures. Since the 10°C tray of lasagna is colder than the 20°C tray of lasagna, it has less thermal energy.