Question

Lily is doing a science experiment with a substance in a sealed jar. At first, the substance's molecules are moving around each other. What will happen to Lily's substance if she transfers energy into the substance and causes a phase change?

Answer 1

The molecules will be more separated, and will have least amount of intermolecular force of attraction.

Explanation:

The molecules inside the jar of Lilly are moving around each other. This means the state of the matter present inside the jar is liquid. As Lily gives more energy inside the jar , the molecules inside the jar will get more separated as the kinetic energy of the molecules increase and the intermolecular force of attraction decreases as well as the intermolecular separation or distance increase. As the energy is continued to be supplied from outside, there will be a time when this liquid will reaches boiling point and will start to change into gas. After this point the intermolecular force of attraction will be least among molecules and their separation will be maximum.