Which one is ionic hydride in nature?

Options

A. CrH
B. `NH_(3)`
C. `H_(2)O`
D. `NaH`

Answer

To determine which of the given options is an ionic hydride, we will analyze each option based on their bonding nature.

### Step-by-Step Solution:

1. **Understanding Ionic vs. Covalent Hydrides**:
- Ionic hydrides are formed when hydrogen combines with highly electropositive metals, resulting in the transfer of electrons and the formation of ions.
- Covalent hydrides are formed when hydrogen combines with nonmetals, resulting in the sharing of electrons.

2. **Analyzing Option A: CRH (Chromium Hydride)**:
- Chromium (Cr) is a transition metal and typically forms covalent bonds.
- In CRH, chromium shares electrons with hydrogen rather than transferring them, indicating that it is a covalent hydride.

3. **Analyzing Option B: NH3 (Ammonia)**:
- Ammonia consists of nitrogen and hydrogen, where nitrogen shares its electrons with hydrogen atoms.
- The bonding in NH3 is covalent due to the sharing of electrons, not ionic.

4. **Analyzing Option C: H2O (Water)**:
- Water is composed of oxygen and hydrogen, where oxygen shares its electrons with hydrogen atoms.
- The bonding in H2O is also covalent, as it involves sharing of electrons.

5. **Analyzing Option D: NAH (Sodium Hydride)**:
- Sodium (Na) is a highly electropositive metal that readily loses an electron to form Na⁺.
- When sodium reacts with hydrogen, it forms Na⁺ and H⁻ (hydride ion), indicating that the bonding involves the transfer of electrons.
- Therefore, NAH is an ionic hydride.

### Conclusion:
The ionic hydride among the given options is **NAH (Sodium Hydride)**.

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