The number of neutrons in deuterium is

Options

A. 0
B. 1
C. 2
D. 3

Answer

To determine the number of neutrons in deuterium, follow these steps:

### Step-by-Step Solution:

1. **Identify the Isotope**:
- Deuterium is an isotope of hydrogen. The notation for deuterium is \( ^2_1H \) or \( ^1H_2 \).

2. **Understand Atomic Number and Mass**:
- The atomic number (Z) of deuterium is 1. This represents the number of protons in the nucleus.
- The atomic mass (A) of deuterium is 2. This represents the total number of protons and neutrons in the nucleus.

3. **Use the Formula to Find Neutrons**:
- The number of neutrons (N) can be calculated using the formula:
\[ N = A - Z \]
- Here, \( A \) is the atomic mass and \( Z \) is the atomic number.

4. **Substitute the Values**:
- For deuterium, substitute the values into the formula:
\[ N = 2 - 1 \]

5. **Calculate the Number of Neutrons**:
- Performing the subtraction gives:
\[ N = 1 \]

6. **Conclusion**:
- Therefore, the number of neutrons in deuterium is 1.

### Final Answer:
The number of neutrons in deuterium is **1**.

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