The semiconductor are generally

Options

A. Monovalent
B. Divalent
C. Trivalent
D. Tetravalent

Answer

To solve the question "The semiconductors are generally," we need to analyze the characteristics of different types of elements based on their valence electrons. Here’s a step-by-step breakdown:

### Step-by-Step Solution:

1. **Understanding Valence Electrons**:
- Elements can be classified based on the number of electrons in their outermost shell (valence shell).
- Monovalent elements have 1 valence electron, divalent elements have 2, trivalent elements have 3, and tetravalent elements have 4.

2. **Identifying Element Types**:
- **Monovalent**: Example is Sodium (Na), which has 1 electron in its outer shell. It can easily lose this electron to conduct electricity.
- **Divalent**: Example is Copper (Cu), which has 2 electrons in its outer shell. It can also conduct electricity by freeing these electrons.
- **Trivalent**: Example is Aluminum (Al), which has 3 electrons in its outer shell. It can conduct electricity as well.
- **Tetravalent**: Example is Silicon (Si), which has 4 electrons in its outer shell.

3. **Conductivity of Tetravalent Elements**:
- Tetravalent elements like Silicon are not good conductors at room temperature because their 4 valence electrons are involved in covalent bonding and are not free to move.
- However, they can conduct electricity when given some energy (thermal energy or light), which excites the electrons and allows them to jump to the conduction band.

4. **Conclusion**:
- Semiconductors are generally tetravalent because they have 4 electrons in their outer shell, which allows them to conduct electricity under certain conditions when energy is supplied.

5. **Final Answer**:
- Therefore, the correct answer is that semiconductors are generally **tetravalent**.