Heavy water is called as heavy because it is

Options

A. A heavy liquid
B. An oxide of heavier isotope of oxygen
C. An oxide of deuterium
D. Less denser than `H_(2)O`

Answer

To answer the question "Heavy water is called as heavy because it is," we need to analyze the options given and understand the properties of heavy water (D2O) compared to regular water (H2O).

### Step-by-Step Solution:

1. **Understanding Heavy Water**:
- Heavy water is chemically represented as D2O, where D stands for deuterium, which is an isotope of hydrogen. Regular water is H2O, which contains regular hydrogen.

2. **Molar Mass Comparison**:
- The molar mass of regular water (H2O) is approximately 18 g/mol.
- The molar mass of heavy water (D2O) is approximately 20 g/mol.
- Since D2O has a higher molar mass than H2O, it is considered "heavy."

3. **Analyzing the Options**:
- **Option A**: "A heavy liquid" - This is vague and does not specifically define heavy water.
- **Option B**: "An oxide of heavier isotope of oxygen" - This is incorrect because heavy water is not an oxide of oxygen; it is an oxide of deuterium.
- **Option C**: "An oxide of deuterium" - This is correct, as heavy water is indeed D2O, which is the oxide of deuterium.
- **Option D**: "Less dense than H2O" - This is incorrect; heavy water is denser than regular water due to its higher mass.

4. **Conclusion**:
- The correct answer is **Option C: An oxide of deuterium**. Heavy water is called "heavy" because it contains deuterium, which makes it denser and gives it a higher molar mass compared to regular water.

### Final Answer:
Heavy water is called heavy because it is an oxide of deuterium (D2O).