What is the relation between diamond and graphite ?

Options

A. Polymorphous
B. Isomer
C. Isotope
D. Isomorphous

Answer

### Step-by-Step Solution:

1. **Definition of Diamond and Graphite**:
- Diamond and graphite are both allotropes of carbon, meaning they are different structural forms of the same element, carbon.

2. **Polymorphism**:
- The term "polymorphous" refers to substances that can exist in more than one form. Carbon is polymorphous because it can exist as diamond and graphite, which have distinct physical properties and structures.

3. **Structural Differences**:
- In diamond, each carbon atom is tetrahedrally bonded to four other carbon atoms, creating a three-dimensional network that is very strong and gives diamond its hardness.
- In graphite, each carbon atom is bonded to three other carbon atoms in flat, two-dimensional layers. These layers can slide over one another, which makes graphite soft and slippery.

4. **Physical Properties**:
- Due to their different structures, diamond is transparent and has a high refractive index, making it brilliant and hard. In contrast, graphite is opaque, conducts electricity, and is used as a lubricant and in pencils.

5. **Chemical Composition**:
- Both diamond and graphite have the same chemical formula (C), but their structural formulas are different, leading to different physical properties.

### Conclusion:
- The relationship between diamond and graphite is that they are both allotropes of carbon, exhibiting polymorphism, with distinct structural and physical properties.

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