# How is carbon monoxide represented?

Generally we represent the carbon monoxide as $\text{sp-hybridized}$. Such a scheme places formal charges on the oxygen and carbon atoms:
""^(-):C-=O:^(+)
There are 5 valence electrons around $C$, hence it has a formal negative charge, but only 5 around $O$, hence it has a formal positive charge. Such a designation can help rationalize why carbon monoxide typically binds to a metal centre via the carbon, e.g. $\left[N i {\left(C O\right)}_{4}\right]$.