The common salt used in food in

Options

A. HCl
B. `Na_(2) CO_(3)`
C. NaCl
D. `CaCl_(2)`

Explanation

**Step-by-Step Solution:**

1. **Identify the Common Salt**: The question asks for the common salt used in food. The most widely recognized common salt is sodium chloride.

2. **Chemical Formula**: Sodium chloride is represented by the chemical formula NaCl. This indicates that it is composed of sodium (Na) and chlorine (Cl) ions.

3. **Ionic Charges**: In sodium chloride, sodium has a charge of +1 (Na⁺) and chlorine has a charge of -1 (Cl⁻). This balance of charges allows them to combine in a 1:1 ratio to form NaCl.

4. **Source of Common Salt**: Sodium chloride is abundantly found in nature, especially in seawater. It is commonly referred to as sea salt because it can be extracted from the ocean.

5. **Extraction and Cost**: The extraction of NaCl from seawater is relatively easy and inexpensive, making it the preferred choice for culinary use. Other salts, such as sodium carbonate (Na₂CO₃) and calcium chloride (CaCl₂), are not used in food due to their different properties and potential health effects.

6. **Conclusion**: Therefore, the common salt used in food is sodium chloride (NaCl).

**Final Answer**: Sodium chloride (NaCl).

---