Answer: 7σ +3π
Step-by-step explanation:
Cumulene has its formular to be C4H4. Structurally it is composed of 4 carbon to Hydrogen single bonds and 3 double bonds.
It is worthy of note that in the field of chemistry:
A double bond is made up of 1σ bond and 1π bond.
A single bond is made up of 1σ bond.
Therefore the structure of Cumulene contains:
4 single bonds = 4σ
3 double bonds = 3 (σ + π )
4σ + 3σ +3π = 7σ +3π