Write the formulae of the following coordination compounds :
potassiumtetracyanonickel(0).

Explanation

To write the formula for the coordination compound potassium tetracyanonickel(0), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Components**:
- The compound consists of potassium ions (K⁺) and a complex ion containing nickel and cyanide ligands.
- The complex ion is tetracyanonickel(0), which indicates that nickel has an oxidation state of 0 and is coordinated by four cyanide (CN⁻) ligands.

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