Calculate the oxidation number of the metals in the following coordination entites `[Co(CN)(H_2O ) (en)_2]^(2+)`

Explanation

To calculate the oxidation number of cobalt in the coordination entity \([Co(CN)(H_2O)(en)_2]^{2+}\), we can follow these steps:

### Step 1: Identify the components of the coordination entity
The coordination entity consists of:
- Cobalt (Co) - the metal whose oxidation number we want to find.
- CN (cyanide) - a negatively charged ligand.
- H2O (water) - a neutral ligand.
- en (ethylene diamine) - a neutral ligand.
...