International General Certificate of Secondary Education (IGCSE) Chemistry Practice Exam

What characterizes the arrangement of particles in a solid?

1. They are far apart and move freely

2. They are close together and regularly packed

3. They are close together but in a disordered arrangement

4. They are sporadic and occupy the available space

The correct answer is: They are close together and regularly packed

The arrangement of particles in a solid is characterized by them being close together and regularly packed. This means that the particles are held tightly in fixed positions, creating a structured and organized arrangement. The regular packing of these particles allows solids to maintain a definite shape and volume, distinguishing them from liquids or gases where the particles are more free to move and less orderly. In solids, the strong intermolecular forces keep the particles in place, preventing them from moving freely, which is significant because it contributes to the rigidity of the solid. This close arrangement allows solids to resist compression and maintain their shape under various conditions. The orderly nature of this arrangement is why solids have a fixed structure compared to the other states of matter, where particle movement and organization vary considerably.