Which among the following is interstitial hydride?

Options

A. `ScH_(2)`
B. `LaH_(2)`
C. `TiH_(1.7)`
D. All of these

Answer

To determine which among the given options is an interstitial hydride, we first need to understand what interstitial hydrides are and the conditions under which they form.

### Step-by-Step Solution:

1. **Definition of Interstitial Hydrides**:
Interstitial hydrides, also known as metallic hydrides or non-stoichiometric hydrides, are formed when hydrogen atoms occupy the interstitial spaces in a metal lattice. These hydrides typically involve transition metals, lanthanides, or actinides.

2. **Formation of Interstitial Hydrides**:
- Interstitial hydrides are formed by the combination of hydrogen with metals, particularly transition metals (except for groups 7, 8, and 9) and lanthanides or actinides.
- The general formula for interstitial hydrides is \( M H_x \), where \( M \) is the metal and \( x \) can be a non-integer value, indicating that the ratio of metal to hydrogen is not fixed.

3. **Analyzing the Options**:
- **Option 1: SC (Scandium)**:
- Scandium is a transition metal (Group 3) and can form interstitial hydrides.
- **Option 2: LA (Lanthanum)**:
- Lanthanum is a lanthanide and can also form interstitial hydrides.
- **Option 3: Ti (Titanium)**:
- Titanium is a transition metal (Group 4) and can form interstitial hydrides as well.
- **Option 4: All of these**:
- Since all the above metals (SC, LA, Ti) can form interstitial hydrides, this option is also valid.

4. **Conclusion**:
Since all the options provided (SC, LA, and Ti) can form interstitial hydrides, the correct answer is **Option 4: All of these**.

### Final Answer:
**Option 4: All of these**