At very low temperature, oxygen `(O_(2))` freezes and forms a crystalline solid. Which term best describes the solid ?

Options

A. Covalent netword crystals
B. Molecular crystals
C. Metallic crystals
D. Ionic crystals

Answer

To determine the best term that describes the crystalline solid formed by oxygen (O₂) at very low temperatures, we need to analyze the nature of the solid based on the characteristics of the bonding and structure involved.

### Step-by-Step Solution:

1. **Identify the Nature of Oxygen (O₂)**:
- Oxygen exists as diatomic molecules (O₂) in its gaseous state. At low temperatures, these molecules can come together to form a solid.

2. **Understand Types of Solids**:
- There are several types of crystalline solids, including:
- **Covalent Network Crystals**: These are formed by atoms connected by covalent bonds in a network (e.g., diamond, silicon carbide).
- **Molecular Crystals**: These are formed by molecules held together by weak intermolecular forces (e.g., dispersion forces, dipole-dipole interactions).
- **Metallic Crystals**: These consist of metal atoms bonded by metallic bonds (e.g., iron, copper).
- **Ionic Crystals**: These are formed by ions held together by ionic bonds (e.g., NaCl, KCl).

3. **Determine the Type of Solid Formed by O₂**:
- Since O₂ is a molecular substance and forms a solid at low temperatures, it will be categorized based on the type of bonding present.
- The forces holding the O₂ molecules together in the solid state are weak dispersion forces, characteristic of molecular crystals.

4. **Conclusion**:
- Based on the analysis, the best term that describes the crystalline solid formed by oxygen (O₂) at very low temperatures is **Molecular Crystals**.

### Final Answer:
The solid formed by oxygen (O₂) at very low temperatures is best described as **Molecular Crystals**.

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