Predict the number of unpaired electrons in the square planar `[Pt(CN)_4]^(2-)` ion.

Explanation

To determine the number of unpaired electrons in the square planar \([Pt(CN)_4]^{2-}\) ion, we can follow these steps:

### Step 1: Determine the oxidation state of platinum (Pt) in the complex.
- The overall charge of the complex is \(-2\).
- Each cyanide (\(CN^-\)) ligand has a charge of \(-1\), and there are four of them, contributing a total charge of \(-4\).
- Let the oxidation state of Pt be \(x\). The equation for the charge balance is:
\[
x + 4(-1) = -2
...