When particles in a substance move faster and occupy larger space without changing to another state of matter, it means the substance is expanding. This expansion is usually due to an increase in temperature.

Here's a breakdown:

* Increased particle motion: When you heat a substance, the particles gain energy and start moving faster.

* Increased spacing: As particles move faster, they collide more frequently and with greater force. This leads to a larger average distance between particles.

* Expansion: The increased spacing between particles translates to an increase in volume.

Examples:

* Heating a balloon: The air inside the balloon heats up, causing the air particles to move faster and spread out. This increases the pressure inside the balloon, making it expand.

* Heating a metal rod: The metal rod expands as its particles vibrate more vigorously and push each other further apart.

Important Note:

While expansion involves particles moving further apart, it doesn't mean the substance changes state (like from solid to liquid or liquid to gas). The particles are still held together by intermolecular forces, just with a bit more space between them.