Scientists digging in a cave found an unknown substance. The scientists found that the substance’s molecules were moving around each other. The scientists
increased the speed of the substance’s molecules and caused a phase change. How
did the scientists do this, and how did this affect the substance?

By adding heat energy

It changed to gas

Explanation:

A substance whose molecules are moving around each other is a liquid. They are held in shape by very weak intermolecular forces.

For solids, there is no movement because the molecules are held up in a fixed lattice.

Gases molecules moves randomly and independently of one another.