Calculate the oxidation number of Ni in `K_(2)[Ni(CN)_(4)]` .

Explanation

To calculate the oxidation number of nickel (Ni) in the complex \( K_2[Ni(CN)_4] \), we can follow these steps:

### Step 1: Identify the components of the complex
The complex consists of potassium ions (K\(^+\)) and the nickel complex ion \([Ni(CN)_4]^{2-}\).

### Step 2: Determine the oxidation state of potassium
Potassium (K) is an alkali metal and has an oxidation number of +1. Since there are 2 potassium ions, their total contribution to the charge is:
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