Draw the structure of diborene $(B_2H_4)$.

(N/A) The structure of diborene $(B_2H_4)$ is analogous to ethene $(C_2H_4)$.
It consists of two boron atoms bonded to each other with a $B-B$ bond length of $134 \text{ pm}$.
Each boron atom is further bonded to two terminal hydrogen atoms with a $B-H$ bond length of $119 \text{ pm}$.
The $H-B-H$ bond angle is approximately $120^{\circ}$, and the $B-B-H$ bond angle is approximately $97^{\circ}$.
The structure is planar, similar to ethene, where the boron atoms are $sp^2$ hybridized.