Which is each pair of elements has a more electronegative gain enthalpy? Explain.
(a) N or O

Explanation

To determine which element between nitrogen (N) and oxygen (O) has a more negative electron gain enthalpy, we need to analyze their electronic configurations and stability.

### Step-by-Step Solution:

1. **Understand Electron Gain Enthalpy**:
- Electron gain enthalpy refers to the energy change when an electron is added to a neutral atom in the gaseous state. This process is exothermic, meaning energy is released, and thus the value is typically expressed as a negative number.

2. **Identify the Electronic Configurations**:
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