Solids can be classified as ______ on the basis of the nature of order present in the arrangement of their constituent particles.

metallic or non-metallic

The correct answer is option 2. metallic or non-metallic.

Solids can be classified as crystalline or amorphous on the basis of the nature of order present in the arrangement of their constituent particles. Therefore, the correct option is crystalline or amorphous.

Let's delve into the explanation of the classification of solids based on the nature of order present in the arrangement of their constituent particles:

1. Crystalline Solids:

Orderly Structure: In crystalline solids, the constituent particles (atoms, ions, or molecules) are arranged in a highly ordered and repeating three-dimensional pattern or lattice.

Definite Melting Point:  Crystalline solids generally have a well-defined melting point, which is the temperature at which the crystal structure breaks down, and the solid transforms into a liquid.

Examples of crystalline solids include salt (sodium chloride), diamond, and quartz.

2. Amorphous Solids:

Random Arrangement: Amorphous solids, on the other hand, lack a well-defined and repeating internal structure. The arrangement of particles is more random and lacks the long-range order seen in crystalline solids.

Gradual Softening:  Amorphous solids often exhibit a gradual softening over a range of temperatures, rather than a distinct melting point.

Examples of amorphous solids include glass, rubber, and some plastics.

The classification into crystalline or amorphous is crucial in understanding the physical properties and behaviors of different types of solids. The arrangement of particles influences properties such as hardness, brittleness, transparency, and conductivity. Additionally, the distinction is important in various scientific and technological applications, ranging from material science to the design of electronic devices.