Heavy water is qualified as heavy liquid as it is.

Options

A. a heavy liquid
B. an oxide of heavier isotope of oxygen
C. an oxide of deuterium
D. denser than water

Answer

To answer the question "Heavy water is qualified as heavy liquid as it is," we will analyze the options provided and determine the correct reasoning behind the classification of heavy water (D2O).

### Step-by-Step Solution:

1. **Understanding Heavy Water**:
- Heavy water is chemically represented as D2O, where D stands for deuterium, an isotope of hydrogen.
- Deuterium has one proton and one neutron in its nucleus, making it heavier than the most common hydrogen isotope (protium, represented as H or 1H), which has only one proton.

2. **Analyzing the Options**:
- **Option 1**: "It is a heavy liquid."
- This statement is vague and does not provide a scientific basis for why heavy water is classified as such. Therefore, it is considered incorrect.

- **Option 2**: "It is an oxide of a heavier isotope of oxygen."
- This statement is incorrect because heavy water is not related to an isotope of oxygen; it is based on the heavier isotope of hydrogen (deuterium).

- **Option 3**: "An oxide of deuterium."
- This statement is correct. Heavy water (D2O) is indeed an oxide of deuterium. It is formed when two deuterium atoms bond with one oxygen atom.

- **Option 4**: "Denser than water."
- While heavy water is denser than regular water (H2O), this option does not explain why it is classified as a heavy liquid. Therefore, it is not the best answer.

3. **Conclusion**:
- The correct answer is **"An oxide of deuterium."** This classification is due to the presence of deuterium, which is heavier than protium, making heavy water a heavy liquid.

### Final Answer:
Heavy water is qualified as a heavy liquid because it is an oxide of deuterium (D2O).

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