Which of the following compounds contains no covalent bond(s)?
`NaCl, PH_(3),O_(2),B_(2)H_(6),H_(2)SO_(4),CaCl_(2)`

Options

A. `NaCl, B_(2)H_(6)`
B. `NaCl, B_(2)H_(6),PH_(3)`
C. `NaCl, H_(2)SO_(4)`
D. `NaCl, CaCl_(2)`

Answer

To determine which of the given compounds contains no covalent bonds, we need to analyze each compound based on the nature of the bonds formed between the atoms.

### Step-by-Step Solution:

1. **Understanding Covalent Bonds**:
- Covalent bonds are formed when two atoms share electrons to achieve a full outer shell (octet). This typically occurs between nonmetals.

2. **Analyzing Each Compound**:
- **NaCl (Sodium Chloride)**:
- Sodium (Na) is a metal and Chlorine (Cl) is a nonmetal. Sodium loses one electron to achieve a full outer shell, and Chlorine gains that electron. This results in the formation of an ionic bond, not a covalent bond.

- **PH3 (Phosphine)**:
- Phosphorus (P) is a nonmetal and forms covalent bonds with three hydrogen (H) atoms by sharing electrons. Thus, PH3 contains covalent bonds.

- **O2 (Oxygen)**:
- Oxygen atoms share two electrons to form a double bond. Therefore, O2 contains covalent bonds.

- **B2H6 (Diborane)**:
- Diborane consists of boron (B) and hydrogen (H) atoms, where boron forms covalent bonds with hydrogen. Thus, B2H6 contains covalent bonds.

- **H2SO4 (Sulfuric Acid)**:
- Sulfur (S) is a nonmetal that forms covalent bonds with four oxygen (O) atoms and two hydrogen (H) atoms. Therefore, H2SO4 contains covalent bonds.

- **CaCl2 (Calcium Chloride)**:
- Calcium (Ca) is a metal and Chlorine (Cl) is a nonmetal. Calcium loses two electrons, and each Chlorine atom gains one electron, resulting in an ionic bond. Thus, CaCl2 contains no covalent bonds.

3. **Conclusion**:
- From the analysis, the compounds that contain no covalent bonds are **NaCl** and **CaCl2**.

### Final Answer:
The compounds that contain no covalent bonds are **NaCl and CaCl2**.

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