Which changes of state are characterized by having atoms that gain energy?

Hey there!

When atoms gain energy, they change to different states of matter. Two changes of state are defined by this concept. They are: boiling, and evaporating.

During boiling, water exceeds or reaches it's boiling point of 212 degrees Fahrenheit and becomes hot. When the atoms reach this point of heat, they gain energy and start to move so fast they become steam, or water in its gaseous form.

Next, we have evaporation. Evaporation is commonly known as a part of the water cycle. When water becomes too hot, atoms gain energy and start becoming gas - eventually to become clouds if we're talking about the cycle.

Hope this helps!