How are particles arranged in a solid?

In a solid, particles are arranged in a tightly packed formation, forming a fixed structure. They are held together by strong intermolecular forces, which are much stronger than those present in liquids and gases. Due to this arrangement, the particles cannot move freely as they do in liquids or gases; instead, they can only vibrate in place around their fixed positions. This limited movement is what gives solids their definite shape and volume.

The concept of tight packing underlies many properties of solids, such as rigidity and incompressibility. As the particles vibrate, they can transfer energy but cannot escape their positions, maintaining the structural integrity of the solid. This is fundamentally different from the behavior of particles in other states of matter, like liquids and gases, where particles are less constrained and can move more freely or even flow past one another.