Ionic Formula for Carbon-12 Ion: C4+ or C4-?

[FeDeX_LaTeX]

Hello;

What is the ionic formula for a carbon-12 ion? It has 4 electrons in its 2nd shell with a capacity of 4, so does that make it C⁴⁺ or C^4-? I think that it is C⁴⁺, because in order for it to bond with the oxygen molecule, O₂, it must be positive, as the oxygen ion is negative... is this reasoning correct?

Also, if I get carbon monoxide, CO, is that not CO²⁺? Because carbon has a charge of +4 and oxygen a charge of -2.

Thanks.

 

[Fermions83]

To answer your question about the carbon monoxide, the carbon is triple bonded to the oxygen, giving the oxygen a formal charge of +1, and the carbon a formal charge of -1, the charges cancel (its neutral), that is why there is no ionic charge on a carbon monoxide molecule.
I am not sure what you mean by the carbon-12 ion problem. As far as I remember, carbon-12 simply means it is a carbon molecule with 6 protons and 6 neutrons, that is why it is called carbon-12, 6+6=12. You are partially correct in saying carbon has 4 electrons in its second shell, it actually has 4 electrons in its second energy level. In the second energy level, the first 2 electrons are in the S orbital, and the last 2 are in the P orbitals.
When carbon bonds with 2 oxygens, it is a similar story as to CO, except the oxygens are both double bonded to carbon, having no formal charges on any of the atoms, are all of there octets are satisfied.

 

[mikelepore]

CO is a molecule, not a polyatomic ion. To figure out the oxidation numbers of the C and O, you begin with the fact that O is -2, and you know that the total has to be zero for any molecule, therefore the oxidation number for C must be +2.

The oxidation number of carbon depends on formula. If it were carbon dioxide instead , we would have to begin with oxygen is -2, and you have two of them, making -4, and the total for the molecule has to be zero, therefore carbon is +4.