Molecules in a solid vibrate rather than move freely like in liquids and gases. They have a fixed position within the solid's structure.

Here's a breakdown:

* Vibration: Molecules in a solid are constantly vibrating. This vibration is rapid and energetic, but the molecules remain in their fixed positions.

* Speed: The speed of the vibrations depends on the temperature. The higher the temperature, the faster the vibrations. However, even at extremely low temperatures, there is still some vibration.

* Fixed Position: The molecules in a solid are held together by strong intermolecular forces, which prevent them from moving freely.

Key points to remember:

* Molecules in solids don't move around freely like in liquids or gases.

* They vibrate within their fixed positions.

* The speed of vibration depends on temperature.

Let me know if you have any other questions!