Generally electron gain enthalpy _____________ on going down a group, and _____________ on going across the period from left to right.

Explanation

To answer the question regarding the trends in electron gain enthalpy, we can break down the solution into clear steps:

### Step-by-Step Solution:

1. **Understanding Electron Gain Enthalpy**:
- Electron gain enthalpy (EGE) is defined as the amount of energy released when an electron is added to a neutral gaseous atom to form a negative ion.

2. **Trend Down a Group**:
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