A solid substance is soft, has a low melting point and is a poor conductor of electricity it is

Options

A. An ionic solid
B. A net work solid
C. A metallic solid
D. A molecular solid

Answer

To determine the type of solid substance described in the question, we will analyze the properties given: it is soft, has a low melting point, and is a poor conductor of electricity.

### Step-by-Step Solution:

1. **Identify the Properties**:
- The substance is described as soft.
- It has a low melting point.
- It is a poor conductor of electricity.

2. **Analyze Softness**:
- Softness typically indicates that the substance does not have strong intermolecular forces holding it together. This rules out ionic and network solids, which are generally hard due to strong ionic bonds or covalent networks.

3. **Consider the Melting Point**:
- A low melting point suggests that the forces holding the particles together are weak. This is characteristic of substances with van der Waals forces, such as molecular solids.

4. **Evaluate Electrical Conductivity**:
- Poor conductivity indicates that the substance does not have free-moving charged particles (like electrons or ions). This further supports the idea that the substance is not ionic or metallic, as both of these types are good conductors of electricity.

5. **Conclusion**:
- Given that the substance is soft, has a low melting point, and is a poor conductor of electricity, the most fitting classification is a **molecular solid**. Molecular solids are held together by weak van der Waals forces, which results in their softness and low melting points.

### Final Answer:
The solid substance is a **molecular solid**.

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