which of the following statement is not correct ?

Options

A. Silicon is extenstively used as a semiconductor
B. Carborundum si ` SiC.`
C. Silicon occurS in free state in nature
D. Mica contains the element silica.

Explanation

To determine which statement is not correct, we will analyze each statement one by one.

1. **Statement A**: "Silicon is extensively used as a semiconductor."
- **Analysis**: This statement is correct. Silicon is widely used in the electronics industry as a semiconductor material. It is essential for the manufacture of various electronic components such as transistors and diodes, including Zener diodes and solar cells.

2. **Statement B**: "Carborundum is SiC."
- **Analysis**: This statement is also correct. Carborundum is indeed silicon carbide (SiC), which is a compound of silicon and carbon. It is known for its hardness and is used in abrasives and as a semiconductor.

3. **Statement C**: "Silicon occurs in the free state in nature."
- **Analysis**: This statement is incorrect. Silicon does not occur in the free state in nature; instead, it primarily exists in the form of silicates or silicon dioxide (SiO2). Silicon is commonly found in minerals and is not found in its elemental form naturally.

4. **Statement D**: "Mica contains the element silica."
- **Analysis**: This statement is correct. Mica is a mineral that contains silicates, which include silicon dioxide (SiO2) as part of its structure. Therefore, it does contain silica.

Based on the analysis, the statement that is not correct is **Statement C**: "Silicon occurs in the free state in nature."

### Final Answer:
The statement that is not correct is **C**: "Silicon occurs in the free state in nature."

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