Final answer:
The boiling of water and the cooling of water vapor are considered reversible processes that can be undone by following the reverse path.
Step-by-step explanation:
The boiling of water and the cooling of water vapor are considered reversible processes. These processes can be reversed by applying the appropriate conditions.
When water boils, it changes from a liquid to a gas. This change can be reversed by cooling the water vapor, causing it to condense back into a liquid. This is a reversible process because it can be undone by following the reverse path.
Similarly, when water vapor cools, it changes from a gas to a liquid. This change can be reversed by heating the liquid, causing it to evaporate back into a gas. Again, this is a reversible process that can be undone by following the reverse path.