Find the ratio of $\pi$-electrons in the C₂ molecule with that of B₂ molecule according to M.O.T.

Here, $\pi$ -electrons in the given molecules are,

${\mathrm{C}}_2-4\pi e^{-}$

${\mathrm{B}}_2-2\pi e^{-}$

Thus, the ratio become,

$$\begin{gathered} \mathrm{r}=\frac{4}{2} \\ \mathrm{r}=2 \end{gathered}$$

Thus, the ratio is 2.