During the change of `O_(2)` to `O_(2)^(-)`, the incoming electron goes to the orbital:

Options

A. `pi 2p_(y)`
B. `sigma**2p_(z)`
C. `pi ** 2p_(x)`
D. `pi 2p_(x)`

Explanation

To solve the question regarding the change of \( O_2 \) to \( O_2^- \) and the orbital to which the incoming electron goes, we can follow these steps:

### Step-by-Step Solution:

1. **Determine the Molecular Orbital Configuration of \( O_2 \)**:
- Oxygen (\( O \)) has an atomic number of 8, which means each oxygen atom contributes 8 electrons. Therefore, \( O_2 \) has a total of \( 8 + 8 = 16 \) electrons.
- The molecular orbital configuration for \( O_2 \) is:
\[ \sigma_{1s}^2 \sigma_{1s}^*^2 \sigma_{2s}^2 \sigma_{2s}^*^2 \sigma_{2p_z}^2 \pi_{2p_x}^2 \pi_{2p_y}^2 \pi_{2p_x}^*^1 \pi_{2p_y}^*^1 \]
- This configuration indicates that the \( O_2 \) molecule has two electrons in the \( \pi^* \) orbitals.

2. **Identify the Lowest Unoccupied Molecular Orbital (LUMO)**:
- In the configuration above, the \( \pi^* \) orbitals (\( \pi_{2p_x}^* \) and \( \pi_{2p_y}^* \)) are the lowest unoccupied molecular orbitals (LUMOs).
- Since both \( \pi_{2p_x}^* \) and \( \pi_{2p_y}^* \) are singly occupied, they can accommodate one more electron.

3. **Determine the Orbital for Incoming Electron**:
- When \( O_2 \) gains an electron to become \( O_2^- \), this incoming electron will occupy one of the \( \pi^* \) orbitals.
- The incoming electron will pair with one of the existing electrons in the \( \pi_{2p_x}^* \) or \( \pi_{2p_y}^* \) orbital.

4. **Final Answer**:
- The incoming electron goes to the \( \pi_{2p_x}^* \) orbital (or equivalently \( \pi_{2p_y}^* \)), but typically we refer to \( \pi_{2p_x}^* \) in such contexts.
- Therefore, the correct answer is that the incoming electron goes to the \( \pi^*_{2p_x} \) orbital.