Question

which item has the least thermal energy?
a. 5 kg cold water
b. 5 kg hot water just below the boiling point
c. 5 kg ice
d. 5 kg boiling water

Explanation:

Thermal energy depends on mass, temperature, and state (for substances with phase changes). All options have the same mass (5 kg). Ice is at a lower temperature (and in a solid state, having less internal energy than liquid water at higher temps). Cold water is warmer than ice, hot water (near boiling) and boiling water are at high temps. So ice has the least thermal energy.

Answer:

C. 5 kg ice