Classification of solids by bonding type On the basis of the dominant chemical bonding, solids may be classified into which groups?

Introduction / Context:Bonding determines a solid’s structure and properties: melting point, electrical conductivity, mechanical behavior, and optical response. A basic taxonomy by bonding helps predict behavior across materials classes used in electronics, structural applications, and chemistry.

Given Data / Assumptions:

• Main bonding types considered: ionic, covalent (valence), metallic, and van der Waals (molecular).
• Network covalent solids (e.g., diamond) versus molecular crystals (e.g., solid CO2) distinguished.
• Hydrogen bonding can be viewed as a special case within molecular crystals.

Concept / Approach:

Ionic crystals feature electrostatic attraction between cations and anions (e.g., NaCl). Covalent (valence) crystals are networks of directional covalent bonds (e.g., diamond, Si). Metals are characterized by a sea of delocalized electrons yielding high electrical/thermal conductivity and ductility. Van der Waals (molecular) crystals are bound by weak intermolecular forces (e.g., noble-gas solids, solid methane), generally soft with low melting points.

Step-by-Step Solution:

Verification / Alternative check:

Standard materials science texts adopt this four-part classification; some add hydrogen-bonded as a subset of molecular/van der Waals solids.

Why Other Options Are Wrong:

Options (a)–(c) omit one or more key classes; (e) is incomplete and misleading.

Common Pitfalls:

Conflating van der Waals molecular crystals with covalent networks; forgetting that real solids can have mixed bonding (classification focuses on the dominant type).

Final Answer:

Ionic crystals, valence (covalent) crystals, metals, and van der Waals (molecular) crystals