Question

How the thermal energy of water changes as it goes through each of the six phase changes that happen on Earth (you can group melting, evaporation and sublimation together as well as freezing, condensation, and deposition)

Answer 1

There are four states of matter in the universe: plasma, gas, liquid and solid. But, matter on Earth exists mostly in three distinct phases: gas, liquid and solid. A phase is a distinctive form of a substance, and matter can change among the phases. It may take extreme temperature, pressure or energy, but all matter can be changed.

There are six distinct changes of phase which happens to different substances at different temperatures. The six changes are:

Freezing: the substance changes from a liquid to a solid.
Melting: the substance changes back from the solid to the liquid.
Condensation: the substance changes from a gas to a liquid.
Vaporization: the substance changes from a liquid to a gas.
Sublimation: the substance changes directly from a solid to a gas without going through the liquid phase.
Deposition: the substance changes directly from a gas to a solid without going through the liquid phase.

Answer 2

Any phase change that takes you from higher energy particles to lower energy particles is exothermic.

Similarly, any phase change that takes you from lower energy particles to higher energy particles is endothermic.

The idea here is that in order to change the state of a substance you must either provide with energy or take away energy.

When you're going from particles that are in a lower energetic state to particles that are in a higher energetic state, you must provide energy.

This implies that the process will be endothermic since heat must be absorbed. You will thus have -- I'll ignore plasma here and stick to the traditional phase changes

solid to liquid →melting→requires an energy liquid to gas →evaporation→requires energy solid to gas →sublimation→requires an energy

When you're going from particles that are in a higher energy state to particles that are in a lower energy state, you must take away energy.

This implies that the process will be exothermic since heat is being released. You will thus have

gas to liquid →condensation→gives off a energy liquid to solid →freezing→gives off an energy gas to solid →deposition→gives off an energy

And there you have it -- six phase changes, three exothermic and three endothermic correspond to the three traditional phases of matter, liquid, solid, and gas.

When you're going from particles that are in a higher energy state to particles that are in a lower energy state, you must take away energy.