Consider `LiH, MgH_2` and `CuH`:

Options

A. All are ionic hydrides
B. LiH, `MgH_(2)` are ionic and CuH is metallic hydride
C. All are covalent hydrides
D. LiH is ionic, `MgH_(2)` and CuH are intermediate hydrides.

Answer

To solve the question regarding the classification of LiH, MgH₂, and CuH, we will analyze each compound based on its chemical properties and the type of hydride it represents.

### Step-by-step Solution:

1. **Identify the Compounds**:
- We have three compounds: Lithium Hydride (LiH), Magnesium Hydride (MgH₂), and Copper Hydride (CuH).

2. **Classify LiH and MgH₂**:
- Both Lithium (Li) and Magnesium (Mg) are elements from the S-block of the periodic table.
- Ionic hydrides are typically formed by S-block elements due to their high electropositivity.
- Therefore, both LiH and MgH₂ are classified as **ionic hydrides**.

3. **Classify CuH**:
- Copper (Cu) is a transition metal, which is part of the D-block of the periodic table.
- Hydrides formed by transition metals are classified as **metallic hydrides**.
- Thus, CuH is classified as a **metallic hydride**.

4. **Summarize the Classifications**:
- LiH: Ionic Hydride
- MgH₂: Ionic Hydride
- CuH: Metallic Hydride

5. **Conclusion**:
- The correct classification is that LiH and MgH₂ are ionic hydrides, while CuH is a metallic hydride. Therefore, the statement that all three are ionic hydrides is incorrect.

### Final Answer:
- LiH and MgH₂ are ionic hydrides, and CuH is a metallic hydride.