The number of neutrons in an atom of hydrogen is

Options

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

Answer

To find the number of neutrons in an atom of hydrogen, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Atomic Number and Mass Number**:
- The atomic number (Z) of hydrogen is 1. This means it has 1 proton.
- The mass number (A) of hydrogen is also 1. The mass number is the total number of protons and neutrons in the nucleus.

2. **Use the Formula for Mass Number**:
- The formula for mass number is given by:
\[ A = P + N \]
where \( A \) is the mass number, \( P \) is the number of protons, and \( N \) is the number of neutrons.

3. **Substitute the Known Values**:
- We know that for hydrogen:
\[ A = 1 \quad \text{and} \quad P = 1 \]
- Substitute these values into the formula:
\[ 1 = 1 + N \]

4. **Solve for Neutrons (N)**:
- Rearranging the equation gives:
\[ N = 1 - 1 \]
\[ N = 0 \]

5. **Conclusion**:
- Therefore, the number of neutrons in an atom of hydrogen is 0.

### Final Answer:
The number of neutrons in an atom of hydrogen is **0**.

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