Which of the following is a covalent compound ?

Options

A. `CaCl_(2)`
B. `H_(2)O`
C. `K_(2)O`
D. `MgO`

Answer

To determine which of the given compounds is a covalent compound, we need to analyze the nature of the bonds formed in each compound. Covalent compounds are formed when atoms share electrons, while ionic compounds are formed when electrons are transferred from one atom to another, resulting in the formation of ions.

### Step-by-Step Solution:

1. **Identify the Compounds**: We will analyze the given compounds. Let's assume the options are:
- A) CaCl2 (Calcium Chloride)
- B) H2O (Water)
- C) K2O (Potassium Oxide)
- D) MgO (Magnesium Oxide)

2. **Analyze CaCl2**:
- Calcium (Ca) has a valency of +2 and Chlorine (Cl) has a valency of -1.
- In CaCl2, calcium loses 2 electrons to form Ca²⁺, and each chlorine atom gains 1 electron to form 2 Cl⁻ ions.
- Since ions are formed, CaCl2 is an **ionic compound**.

3. **Analyze H2O**:
- Oxygen (O) has 6 electrons in its outer shell and needs 2 more to complete its octet. Each Hydrogen (H) atom has 1 electron.
- Oxygen shares its electrons with 2 Hydrogen atoms, forming covalent bonds.
- Since electrons are shared, H2O is a **covalent compound**.

4. **Analyze K2O**:
- Potassium (K) has a valency of +1 and Oxygen (O) has a valency of -2.
- In K2O, 2 potassium atoms lose 1 electron each to form 2 K⁺ ions, while oxygen gains 2 electrons to form O²⁻.
- Since ions are formed, K2O is an **ionic compound**.

5. **Analyze MgO**:
- Magnesium (Mg) has a valency of +2 and Oxygen (O) has a valency of -2.
- In MgO, magnesium loses 2 electrons to form Mg²⁺ and oxygen gains 2 electrons to form O²⁻.
- Since ions are formed, MgO is an **ionic compound**.

6. **Conclusion**:
- Among the options analyzed, **H2O (Water)** is the only compound that is a covalent compound.

### Final Answer:
**B) H2O is a covalent compound.**