Which of the following are ionic carbides ?

Options

A. `CaC_(2)`
B. `Al_(4)C_(3)`
C. `SiC`
D. `Be_(2)C`

Explanation

To determine which of the given options are ionic carbides, we need to understand the nature of carbides and the difference between ionic and covalent bonds.

### Step-by-Step Solution:

1. **Understanding Carbides**:
- Carbides are compounds that consist of carbon and a more electropositive element (usually a metal).
- They can be classified into two main types: ionic carbides and covalent carbides.

2. **Identifying Ionic Carbides**:
- Ionic carbides are formed when there is a significant difference in electronegativity between the metal and carbon, leading to the transfer of electrons from the metal to carbon.
- Metals that are electropositive (like alkali and alkaline earth metals) typically form ionic carbides.

3. **Examples of Ionic and Covalent Carbides**:
- Common ionic carbides include those formed with metals like calcium (CaC2), aluminum (Al4C3), and barium (BaC2).
- Covalent carbides include silicon carbide (SiC) and boron carbide (B4C), which are formed through sharing of electrons rather than transfer.

4. **Analyzing the Given Options**:
- Check each option to see if they contain a highly electropositive metal with carbon.
- If they do, they are likely ionic carbides.

5. **Conclusion**:
- Based on the analysis, the options that contain metals like calcium, aluminum, or barium with carbon will be classified as ionic carbides.
- Therefore, the answer will include the first, second, and fourth options as ionic carbides.

### Final Answer:
The ionic carbides among the given options are: **Option 1, Option 2, and Option 4**.