The EAN of `Mo(CO)_(6)` is ______________

Explanation

To find the Effective Atomic Number (EAN) of the complex \( \text{Mo(CO)}_6 \), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Central Metal and Its Atomic Number**:
- The central metal in the complex \( \text{Mo(CO)}_6 \) is Molybdenum (Mo).
- The atomic number (Z) of Molybdenum is 42.

2. **Determine the Oxidation State of the Metal**:
- In this complex, carbon monoxide (CO) is a neutral ligand, which means it does not contribute to the oxidation state.
- Therefore, the oxidation number of Molybdenum in \( \text{Mo(CO)}_6 \) is 0.

3. **Identify the Coordination Number**:
- The coordination number is the number of ligands attached to the central metal.
- In \( \text{Mo(CO)}_6 \), there are 6 CO ligands, so the coordination number is 6.

4. **Apply the EAN Formula**:
- The formula for EAN is given by:
\[ \text{EAN} = Z - \text{Oxidation Number} + 2 \times \text{Coordination Number} \]
- Substituting the values we have:
\[ \text{EAN} = 42 - 0 + 2 \times 6 \]
- Calculate \( 2 \times 6 = 12 \).

5. **Calculate the Effective Atomic Number**:
- Now, substituting back into the equation:
\[ \text{EAN} = 42 + 12 = 54 \]

Thus, the Effective Atomic Number (EAN) of \( \text{Mo(CO)}_6 \) is **54**.