Question

How many sigma and pi bonds are present in a molecule of cumulene?

Answer 1

`7sigma + 3pi`

Explanation:

This is a molecule of cumulene, `C_4H_4`.

Single bonds are one `sigma`-bond, while double bonds are one `sigma` and one `pi`-bond.

`sigma` and `pi`-bonds are just ways in which electron orbitals interact to form bonds - `sigma` are stronger bonds, but you can't have more than one between the same two atoms.

Cumulene has three double bonds and four single bonds, or,

`3(sigma + pi) + 4sigma = 7sigma + 3pi`