Which of the following compounds does not follow the octet rule for electron distribution?

Does $CO_2$ contain multiple bonds? If so,identify them.

Hydrogen atoms are held together to form hydrogen molecules by

The $X-X$ bond length is $1.00 \mathring{A}$ and $C-C$ bond length is $1.54 \mathring{A}$. If $EN$ of $X$ and $C$ are $3.0$ and $2.0$ respectively,the $C-X$ bond length is likely to be ............ $\mathring{A}$.

Which of the following elements can be involved in $p \pi-d \pi$ bonding with oxygen?

Explain the Valence Bond Theory $(VBT)$.