What is the oxidation number of the metal in #Ni(CO)_4#?
Well, we should review the definition of
The oxidation state of an atom in a compound is the charge left on the atom when all the bonding pairs of electrons are removed, with the charge, the electron, assigned to the more electronegative atom. This goes back to our earliest definitions of ionic and covalent bonding, where ionic bonds result from the transfer of electrons between atoms to give ions, and covalent bonds result from the sharing of electrons to form bonds...........
And when we do this for