out of carbon (diamond)and carbon (graphite), whose enthalpy of formation is taken as zero and why?

Explanation

To determine which form of carbon, diamond or graphite, has an enthalpy of formation taken as zero, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Enthalpy of Formation**:
- The enthalpy of formation of a substance is defined as the change in enthalpy when one mole of a compound is formed from its elements in their standard states.

2. **Standard State and Stability**:
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