Gallium melts at 29.76oC, low enough to melt in your hand. Before gallium can melt, there is a mixture of solid and liquid at the same temperature, as in the figure. Which physical state of gallium has more thermal energy? Explain how you know.
Both the solid and liquid states have the same amount of thermal energy.
The liquid state has more thermal energy because its particles are free to move.
It is impossible to determine which state has more thermal energy without additional information.
The solid state has more thermal energy because its particles are tightly packed.
The correct answer is: The liquid state has more thermal energy because its particles are free to move.
In the solid state, the particles are tightly packed and vibrate in fixed positions. They have a lower amount of thermal energy because they have less freedom to move.
In the liquid state, the particles have more thermal energy because they have more freedom to move. They can flow and slide past each other, which allows them to possess more kinetic energy.