In which of the following set do all the three compunds have bonds that are mainly ionic:-

Options

A. `NaCl, NCl_(3), C Cl_(4)`
B. `CsBr, BaBr_(2), SrO`
C. `CsF, BF_(3), NH_(3)`
D. `Al_(2)O_(3), CaO, SO_(2)`

Explanation

To determine which set of compounds contains all ionic bonds, we need to analyze each option provided.

### Step-by-Step Solution:

1. **Identify the Compounds in Each Option:**
- Option A: NaCl, NCl3, KCl
- Option B: CsBr, BaBr2, SrO
- Option C: CsF, Al2O3, CO2

2. **Analyze Option A:**
- **NaCl:** Sodium chloride is an ionic compound (Na⁺ and Cl⁻).
- **NCl3:** Nitrogen trichloride has covalent bonds. Nitrogen shares electrons with chlorine, making this compound covalent.
- **KCl:** Potassium chloride is also ionic (K⁺ and Cl⁻).
- **Conclusion:** Since NCl3 is covalent, Option A is not correct.

3. **Analyze Option B:**
- **CsBr:** Cesium bromide is ionic (Cs⁺ and Br⁻).
- **BaBr2:** Barium bromide is ionic (Ba²⁺ and 2Br⁻).
- **SrO:** Strontium oxide is ionic (Sr²⁺ and O²⁻).
- **Conclusion:** All compounds in Option B are ionic, so this option is correct.

4. **Analyze Option C:**
- **CsF:** Cesium fluoride is ionic (Cs⁺ and F⁻).
- **Al2O3:** Aluminum oxide has both ionic and covalent character but is primarily ionic (Al³⁺ and O²⁻).
- **CO2:** Carbon dioxide is covalent (C shares electrons with O).
- **Conclusion:** Since CO2 is covalent, Option C is not correct.

5. **Final Conclusion:**
- The only set where all three compounds are mainly ionic is **Option B (CsBr, BaBr2, SrO)**.

### Final Answer:
The correct option is **B: CsBr, BaBr2, SrO**.