A: Zn (II) salts are diamagnetic
R : `Zn^(2+)` ion has one unpaired electron.

Options

A. IF both assertion & reason are true and the reason is the correct explanation of the assertion then mark
B. IF both assertion & reason are true but the reason is not the correct explanation of the assertion , then mark
C. IF assertion is true statement but reason is false , then mark
D. If both assertion and reason are false statements then mark

Answer

To solve the question regarding the assertion and reason about zinc (II) salts and the Zn²⁺ ion, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Terms:**
- **Diamagnetic:** A substance is considered diamagnetic if it has no unpaired electrons. Diamagnetic substances are not attracted to a magnetic field.
- **Paramagnetic:** A substance is considered paramagnetic if it has at least one unpaired electron. Paramagnetic substances are attracted to a magnetic field.

2. **Determine the Electronic Configuration of Zinc:**
- The atomic number of zinc (Zn) is 30. The electronic configuration of neutral zinc is:
\[ \text{Zn: } 1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^6 \, 3d^{10} \, 4s^2 \]

3. **Determine the Electronic Configuration of Zn²⁺:**
- When zinc loses two electrons to form the Zn²⁺ ion, the electrons are removed from the outermost shell (4s before 3d). Thus, the electronic configuration for Zn²⁺ is:
\[ \text{Zn}^{2+}: 1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^6 \, 3d^{10} \]
- This indicates that all the electrons in the 3d subshell are paired.

4. **Analyze the Assertion:**
- The assertion states that Zn(II) salts are diamagnetic. Since Zn²⁺ has no unpaired electrons (as shown in the electronic configuration), this assertion is **true**.

5. **Analyze the Reason:**
- The reason states that the Zn²⁺ ion has one unpaired electron. This is **false** because, as we determined, Zn²⁺ has all paired electrons.

6. **Conclusion:**
- The assertion is true, but the reason is false. Therefore, the correct answer to the question is that the assertion is true, and the reason is false.