Which of the following is heavy water ?

Options

A. `H_2O`
B. `D_2O`
C. `T_2O`
D. Water at ` 0^@`

Answer

To determine which of the following is heavy water, we need to understand the concept of heavy water and its composition.

### Step-by-Step Solution:

1. **Understanding Heavy Water**:
- Heavy water is a form of water that contains a larger proportion of the hydrogen isotope deuterium (D) instead of the more common hydrogen isotope protium (H).

2. **Composition of Heavy Water**:
- Normal water (H₂O) consists of two hydrogen atoms (H) and one oxygen atom (O).
- In heavy water, the hydrogen atoms are replaced by deuterium atoms. Deuterium has one proton and one neutron in its nucleus, giving it a mass of 2.

3. **Chemical Formula of Heavy Water**:
- The chemical formula for heavy water is D₂O, where D represents deuterium.

4. **Identifying Heavy Water**:
- Among the options provided, we need to look for the formula that corresponds to D₂O.

5. **Conclusion**:
- The correct answer is the option that represents D₂O, which is heavy water.