The conduction band and valence band in a good conductor

Options

A. Are well separated by a forbidden band
B. are overlapped
C. Some times overlap and sometimes separated
D. Have forbidden band

Answer

To solve the question regarding the conduction band and valence band in a good conductor, we will follow these steps:

### Step 1: Understand the Concept of Energy Bands
In solid-state physics, materials are characterized by energy bands, which are ranges of energy levels that electrons can occupy. The two most important bands are the valence band and the conduction band.

### Step 2: Define Valence Band and Conduction Band
- **Valence Band**: This is the highest range of energy levels that are filled with electrons at absolute zero temperature.
- **Conduction Band**: This is the range of energy levels that are typically empty at absolute zero but can be filled with electrons when energy is provided (for example, through heat or light).

### Step 3: Understand the Band Gap
The **band gap** (or forbidden band) is the energy difference between the top of the valence band and the bottom of the conduction band. In conductors, this band gap is either very small or non-existent.

### Step 4: Analyze Conductors
In good conductors (like silver and copper), the conduction band and valence band overlap. This means that electrons can easily move from the valence band to the conduction band without needing extra energy to overcome a band gap.

### Step 5: Conclusion
Since the conduction band and valence band in a good conductor overlap, the correct answer to the question is that they are "overlapped."

### Final Answer
The conduction band and valence band in a good conductor are overlapped.

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