Answer:
When Brock put 3 cups of water in a pot on the stove and turned it on to "high," the heat caused the water to evaporate. Evaporation is the process in which a liquid turns into a gas. As the water reached its boiling point, the heat supplied by the stove caused the water molecules to gain enough energy to break free from their liquid state and transform into water vapor.
Explanation:
Once the water started to boil, some of it escaped as steam. Steam is the gaseous form of water. This process continued for a few minutes until Brock took the pot off the stove. When the pot was removed from the heat source, the remaining water began to cool down.
As the water cooled, the water vapor molecules lost energy and condensed back into a liquid. The condensed water droplets then collected inside the pot. This is why when Brock measured the water again after it had cooled, there was only 2 3/4 cups left instead of the initial 3 cups. The difference in the amount of water can be attributed to the water that evaporated during the boiling process.
In summary, the water evaporated and turned into steam due to the heat applied on the stove. After cooling down, the steam condensed back into a liquid, resulting in a decrease in the amount of water in the pot