Chemistry Definition in your own words
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Word: Phase change

See explanation.

Explanation:

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In this case, considering the concept of phase change, we understand that it is related how the phases of matter, solid, liquid and gas, are related to each other for a specific substance.

For instance, when going over water, we notice that its most common phase at this atmospheric conditions is the liquid phase; however, if it starts losing energy (being cooled down) its molecules tend to get together and freeze, undergoing a phase change to solid. On the other hand, if heated up, its molecules will be able to get farther to each other and therefore undergo a phase change to gas.

Thus, we can realize that a phase change is also explained molecularly; because when a substance undergo a phase change, its molecules rearrange, according to the addition or removal of energy and therefore get to another phase.

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