The problem to solve is to formulate in which way two carbon atoms are described by using atomic orbitals.
First one has to find out the electronic structure of a carbon atom by locating this element in the periodic table.
Second step is then to fill the orbitals with the given number of electrons using Hund's rule.
The third step contains the formation of bonds between the atoms under respect of bonding and antibonding molecular orbitals.
With these given information the bond order is being calculated then.
In this solution is explained in which way the bond of C2 (2-) can be explained by using the MO - diagram. Main focus lies on the explanation of how to find the answer when starting from single atoms and their atom orbitals. This is being made by a step-by-step explanation using the needed rules of theory.