Question

How do molecules change with temperature?

Answer 1

At low temperatures, molecular motion decreases and substances have less internal energy. Atoms will settle into low energy states relative to one another and move very little, which is characteristic of solid matter. As temperatures increase, additional heat energy is applied to the constituent parts of a solid, which causes additional molecular motion. Molecules begin to push against one another and the overall volume of a substance increases. At this point, the matter has entered the liquid state. A gaseous state exists when molecules have absorbed so much heat energy due to increased temperatures that they are free to move around one another at high speeds.