The mass number A, atomic number Z and number of neutrons n are related as

Options

A. n= A-Z
B. n = A + Z
C. n= A`xx`Z
D. none of these.

Explanation

To find the relationship between the mass number (A), atomic number (Z), and the number of neutrons (N), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Definitions**:
- The **mass number (A)** is the total number of protons and neutrons in the nucleus of an atom.
- The **atomic number (Z)** is the number of protons in the nucleus of an atom.
- The **number of neutrons (N)** can be calculated by subtracting the number of protons from the mass number.

2. **Establishing the Relationship**:
- The relationship can be expressed mathematically as:
\[ A = Z + N \]
- Here, A is the mass number, Z is the atomic number, and N is the number of neutrons.

3. **Rearranging the Equation**:
- To find the number of neutrons (N), we can rearrange the equation:
\[ N = A - Z \]

4. **Conclusion**:
- The relationship between mass number (A), atomic number (Z), and number of neutrons (N) can be summarized as:
\[ N = A - Z \]

### Final Answer:
The mass number (A), atomic number (Z), and number of neutrons (N) are related by the equation:
\[ N = A - Z \]