The bond energy of `H_(2)` is found to be 435 kJ `mol^(-1)`. Therefore, the enthalpy of formation of hydrogen atom will be `"…................"`

Explanation

To find the enthalpy of formation of a hydrogen atom from hydrogen gas (H₂), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Bond Energy**: The bond energy of H₂ is given as 435 kJ/mol. This value represents the energy required to break one mole of H₂ molecules into two moles of hydrogen atoms (H).

2. **Write the Reaction**: The dissociation of hydrogen gas into hydrogen atoms can be represented as:
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