Give different forms in which carbon occurs in nature.

Explanation

To answer the question about the different forms in which carbon occurs in nature, we can break it down into two main categories: free forms and combined forms.

### Step-by-Step Solution:

1. **Identify the Free Forms of Carbon:**
- Carbon occurs in nature in two primary free forms: graphite and diamond.
- **Graphite:**
- Graphite has a layered, sheet-like structure and is known for its lubricating properties and electrical conductivity.
- It is a 2D structure, where carbon atoms are arranged in hexagonal patterns.
- **Diamond:**
- Diamond has a tetrahedral structure, where each carbon atom is bonded to four other carbon atoms in a 3D arrangement.
- It is known for its hardness and is often used in cutting tools and jewelry.

2. **Identify the Combined Forms of Carbon:**
- Carbon also exists in various combined forms:
- **Carbon Dioxide (CO2):**
- This is a gas that is formed when carbon combusts in the presence of oxygen. It is essential for photosynthesis in plants.
- **Carbonates:**
- Carbon can be found in the form of carbonates, such as calcium carbonate (CaCO3) found in limestone and shells.
- **Organic Compounds:**
- Carbon is a fundamental component of all organic compounds, which include hydrocarbons, sugars, proteins, and fats.

3. **Summarize the Forms:**
- In summary, carbon occurs in nature in the following forms:
- **Free Forms:** Graphite, Diamond
- **Combined Forms:** Carbon Dioxide (CO2), Carbonates, Organic Compounds

### Final Answer:
Carbon occurs in nature in the following forms:
- **Free Forms:**
- Graphite
- Diamond
- **Combined Forms:**
- Carbon Dioxide (CO2)
- Carbonates (e.g., Calcium Carbonate)
- Organic Compounds

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