Which object has less thermal energy?
a 350-gram mug of cocoa at a temperature of 30°C a 350-gram mug of cocoa at a temperature of 65°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 mugs of cocoa have the same mass but different temperatures. Since the 30°C mug of cocoa is colder than the 65°C mug of cocoa, it has less thermal energy.