When ice is left outside on a hot day, it melts, and then evaporates. Which best describes what happens to the molecules in the ice?

The molecules have a higher average kinetic energy after each of the phase changes.

The molecules move faster after the first phase change, but then start to move more slowly.

The molecules lose energy in the first phase change, but gain it back in the second phase change.

The molecules convert their kinetic energy into heat energy to cause the phase change.

Question

When ice is left outside on a hot day, it melts, and then evaporates. Which best describes what happens to the molecules in the ice?

 The molecules have a higher average kinetic energy after each of the phase changes.

 The molecules move faster after the first phase change, but then start to move more slowly.

 The molecules lose energy in the first phase change, but gain it back in the second phase change.

 The molecules convert their kinetic energy into heat energy to cause the phase change.

anonymous · Answer

The molecules will have a higher average kinetic energy because after each state the molecules will have more energy to overcome the bonds that hold them together to for a solid and then a liquid. Also, I don't think the last one is right because the movement of particles is their movement and kinetic energy. So it doesn't really seem right to me.

anonymous · Answer

temperature is a measure of kinetic energy.  the hotter a substance gets, the faster it moves.  when it evaporates, the molecules are moving at a faster rate than they were as a liquid because of the heat being added.  therefore, the kinetic energy increased.