Among the alkali metal hydrides, which hydride is most stable ?

Explanation

To determine which alkali metal hydride is the most stable, we can analyze the stability trend of alkali metal hydrides (MH, where M is an alkali metal).

### Step-by-Step Solution:

1. **Identify the Alkali Metal Hydrides**: The alkali metals include Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), and Cesium (Cs). The corresponding hydrides are LiH, NaH, KH, RbH, and CsH.

2. **Understand Stability Trends**: The stability of these hydrides can be compared based on their lattice energy, which is influenced by the size of the cation (the alkali metal ion).

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