Which of these is present in various froms in the Earth's crust?

Options

A. Iron
B. Gold
C. Silica
D. Platinum

Answer

**Step-by-Step Text Solution:**

1. **Identify the Options**: The question presents four options: iron, gold, silica, and platinum. We need to determine which of these is present in various forms in the Earth's crust.

2. **Understanding Silica**: Silica is a compound made up of silicon and oxygen (SiO2). It is known for its presence in various forms in nature.

3. **Forms of Silica**: Silica can be found in different crystalline forms, including:
- Quartz
- Tridymite
- Cristobalite

4. **Presence in Earth's Crust**: Silica is a major component of the Earth's crust, constituting about 59% of it. This indicates its abundance and the various forms it can take.

5. **Conclusion**: Based on the information, the correct answer to the question is silica, as it is present in various forms in the Earth's crust.

**Final Answer**: Silica

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