Which object has more thermal energy?
a 5-kilogram block of iron at a temperature of 75°C a 5-kilogram block of iron at a temperature of 70°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 move faster, the temperature goes up. The matter now has both more thermal energy and a higher temperature.
The two blocks of iron have the same mass but different temperatures. Since the 75°C block is hotter than the 70°C block, it has more thermal energy.