what you mean by semi conductor

Answer

### Step-by-Step Text Solution:

1. **Definition of Semiconductor**:
- A semiconductor is a material that has electrical conductivity between that of a conductor (like metals) and an insulator (like most ceramics).

2. **Conductivity Range**:
- Conductors have high conductivity, allowing electricity to flow easily. Insulators have very low conductivity, preventing the flow of electricity. Semiconductors fall in between these two categories.

3. **Types of Semiconductors**:
- Semiconductors can be pure elements or compounds.
- **Pure Elements**: Examples include silicon (Si) and germanium (Ge).
- **Compounds**: Examples include gallium arsenide (GaAs) and cadmium selenide (CdSe).

4. **Applications of Semiconductors**:
- Semiconductors are widely used in various electronic devices. For instance, gallium arsenide is commonly used in laser diodes, solar cells, and microwave frequency integrated circuits.

5. **Position in the Periodic Table**:
- Silicon is one of the most well-known semiconductors, and gallium arsenide is noted as the second most common semiconductor after silicon.