The temperature determines the state of a substance. When heated enough, a solid changes to a LIQUID, and a liquid to a gas. These changes of state TAKE places because the molecules, or tiny bits of matter than MAKE up the substance, vibrate faster when the substance is heated (kinetic ENERGY increases). When the molecules vibrate faster, the attractive FORCES that hold the molecules together are broken. When cooled (this is the process of losing heat), a gas changes to a liquid, and a liquid changes to a solid.

The temperature determines the state of a substance. When heated enough, a solid changes to a liquid, and a liquid to a gas. These changes of state take places because the molecules, or tiny bits of matter than make up the substance, vibrate faster when the substance is heated (kinetic energy increases). When the molecules vibrate faster, the attractive forces that hold the molecules together are broken. When cooled (this is the process of losing heat), a gas changes to a liquid, and a liquid changes to a solid.