Provide the electron configuration,magnetic property,bond order,and energy level diagram for the carbon molecule $(C_2)$.

(N/A) $C_2$ $(Z=6)$ has an atomic configuration of $1s^2 2s^2 2p^2$. Thus,the total number of electrons in $C_2$ is $12$.
Molecular orbital $(MO)$ electron configuration for $C_2$:
$(\sigma 1s)^2 (\sigma^* 1s)^2 (\sigma 2s)^2 (\sigma^* 2s)^2 (\pi 2p_x)^2 (\pi 2p_y)^2$ or $KK(\sigma 2s)^2 (\sigma^* 2s)^2 (\pi 2p_x)^2 (\pi 2p_y)^2$.
Bond order $= \frac{1}{2} (N_b - N_a) = \frac{1}{2} (8 - 4) = 2$.
Magnetic Property: All electrons are paired,therefore,it is diamagnetic.
Note: In the $C_2$ molecule,both bonds in the double bond are $\pi$-bonds.
Energy level diagram for $C_2$ molecule: