Why the electron gain enthalpy values of alkaline earth metals are lower (i.e. less negative) or positive?

Explanation

**Step-by-Step Solution:**

1. **Understanding Electron Gain Enthalpy**:
- Electron gain enthalpy is the amount of energy released when an electron is added to a neutral atom in the gas phase. A more negative value indicates a greater tendency to gain an electron.

2. **Electronic Configuration of Alkaline Earth Metals**:
- The alkaline earth metals (Group 2 elements) have the general electronic configuration of \( ns^2 \). This means they have two electrons in their outermost shell.

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