Science Common Sense

1075 - Why does the state of matter change with temperature?

Imagine the tiny particles of a substance, like atoms or molecules. They are always moving, or 'vibrating'. When the temperature changes, these particles either get more or less energy.

• When the temperature goes up, the particles get more energy and move faster. If they move fast enough, they can break free from their bonds with other particles, turning from solid to liquid (melting), or from liquid to gas (evaporating).
• When the temperature goes down, the particles get less energy and move slower. This allows them to bond together more tightly, turning from gas to liquid (condensing), or from liquid to solid (freezing).