The percentage of deuterium in heavy water is

Options

A. 22.2
B. 11.2
C. 44
D. 20

Explanation

To find the percentage of deuterium in heavy water (D₂O), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Composition of Heavy Water**:
- Heavy water (D₂O) consists of two deuterium (D) atoms and one oxygen (O) atom.

2. **Determine the Molar Mass of Deuterium**:
- The molar mass of deuterium (D) is approximately 2 g/mol.

3. **Calculate the Total Mass of Deuterium in Heavy Water**:
- Since there are two deuterium atoms in heavy water, the total mass of deuterium in D₂O is:
\[ \text{Total mass of D} = 2 \, \text{(mass of D)} \times 2 \, \text{(number of D atoms)} = 4 \, \text{g} \]

4. **Determine the Molar Mass of Oxygen**:
- The molar mass of oxygen (O) is approximately 16 g/mol.

5. **Calculate the Total Mass of Heavy Water (D₂O)**:
- The total mass of heavy water is the sum of the mass of deuterium and the mass of oxygen:
\[ \text{Total mass of D₂O} = \text{mass of D} + \text{mass of O} = 4 \, \text{g} + 16 \, \text{g} = 20 \, \text{g} \]

6. **Calculate the Percentage of Deuterium in Heavy Water**:
- The percentage of deuterium in heavy water can be calculated using the formula:
\[ \text{Percentage of D} = \left( \frac{\text{mass of D}}{\text{total mass of D₂O}} \right) \times 100 \]
- Plugging in the values:
\[ \text{Percentage of D} = \left( \frac{4 \, \text{g}}{20 \, \text{g}} \right) \times 100 = 20\% \]

### Final Answer:
The percentage of deuterium in heavy water is **20%**.

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