Question

The magnetic moment of a salt containing Zn\(^{2+}\) ion is

• A. 0
• B. 1.87
• C. 5.92
• D. 2

Hint:

Ions with completely filled subshell (like \(d^{10}\)) have zero unpaired electrons and are diamagnetic.

Answer 1

The Correct Option is A

Step 1: Write electronic configuration of Zn\(^{2+}\).
Zn (Z=30) has configuration:
\[ Zn: [Ar]\,3d^{10}4s^2 \]
Zn\(^{2+}\) loses two 4s electrons:
\[ Zn^{2+}: [Ar]\,3d^{10} \]
Step 2: Check unpaired electrons.
\(3d^{10}\) means all d-orbitals are completely filled.
So there are no unpaired electrons.
Step 3: Magnetic moment.
Magnetic moment depends on unpaired electrons:
\[ \mu = \sqrt{n(n+2)} \]
Here \(n=0\), so:
\[ \mu = 0 \]
Final Answer:
\[ \boxed{0} \]