Silicon is

Options

A. semi-conductor
B. conductor
C. Insulator
D. None of these

Explanation

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks to identify what silicon is among the options: semiconductor, conductor, insulator, or anode.

2. **Defining Terms**:
- **Conductor**: A material that allows electricity to flow freely due to the presence of free electrons.
- **Insulator**: A material that does not allow electricity to flow because it lacks free electrons.
- **Semiconductor**: A material that has conductivity between that of a conductor and an insulator. It does not conduct electricity well at low temperatures but can conduct electricity at higher temperatures.
- **Anode**: An electrode through which current flows into a polarized electrical device.

3. **Properties of Silicon**:
- Silicon has an atomic number of 14 and an electronic configuration of [Ne] 3s² 3p².
- It has four valence electrons, which allows it to form covalent bonds with other silicon atoms.

4. **Behavior of Silicon**:
- At low temperatures, silicon behaves like an insulator because it does not have enough energy to allow electrons to move freely.
- As the temperature increases, silicon can conduct electricity better because the added thermal energy allows some electrons to jump into the conduction band, creating free charge carriers.

5. **Conclusion**: Based on its properties and behavior, silicon is classified as a semiconductor. Therefore, the correct answer is option number 1: **semiconductor**.