The number of neutrons in the dipositive zinc ion (Mass no. of Zn = 65)

Options

A. 35
B. 33
C. 65
D. 67

Answer

To find the number of neutrons in the dipositive zinc ion (Zn²⁺), we can follow these steps:

### Step 1: Identify the Mass Number and Atomic Number
- The mass number of zinc (Zn) is given as 65.
- The atomic number of zinc (Zn) is 30, which indicates the number of protons in a neutral zinc atom.

### Step 2: Determine the Number of Protons
- In a neutral zinc atom, the number of protons is equal to the atomic number. Therefore, the number of protons in zinc is:
\[ \text{Number of protons} = \text{Atomic number of Zn} = 30 \]

### Step 3: Use the Mass Number to Find the Number of Neutrons
- The mass number (A) is the sum of the number of protons (Z) and the number of neutrons (N):
\[ A = Z + N \]
- Rearranging the equation to solve for the number of neutrons gives us:
\[ N = A - Z \]

### Step 4: Substitute the Known Values
- Substitute the mass number (65) and the number of protons (30) into the equation:
\[ N = 65 - 30 \]

### Step 5: Calculate the Number of Neutrons
- Performing the calculation:
\[ N = 35 \]

### Conclusion
- Therefore, the number of neutrons in the dipositive zinc ion (Zn²⁺) is **35**.

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