A scientist has a container with a substance inside. At first, the molecules in the substance move away from each other. Later, the molecules move around each other. What change did the scientist observe in the substance?

Base on the properties the substances possess the substance change phase from gas to liquid.

Explanation:

Generally, matter can exist in three phase namely liquid , solid and gas. The scientist has a container with a substance inside.

At first the substance moves away from each other . This means the substance was first in the gas phase . Gas molecules, because of the energy they possess , it can move rapidly and randomly and most at times move away from each other . The gas molecules tends to fill the whole volume of the container and the shape of gases are indefinite.

Later the molecules move around each other. This is a property of a liquid . A substance in liquid phase have the ability to move freely but they stay together because of the force of attraction holding them together . The substance only have the ability to move around each other because the forces holding them together won't allow them to move apart.

Base on the properties the substances possess the substance change phase from gas to liquid.

The observed change is simple.

When a substance such as water is in gaseous form, its molecules move away from one another, however, when it begins to solidify (sometimes) first into liquid then into Ice (which is solid). At this point the molecules have become closer and around one another.

Increasing heat can make a solid like ice to melt to form water (a liquid). Reducing the heat on the other hand  causes water (a liquid) to freeze to form ice (a solid). When water changes to a solid or a gas, we say it changes to a different state of matter. Even though the water's physical form changes, its molecules remain the same.

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