ACS Chemistry Practice Exam 2026 – The All-in-One Guide to Exam Success!

A double bond consists of one sigma bond and one pi bond.

The sigma bond is formed from the head-on overlap of atomic orbitals, which allows for the electron density to be concentrated along the axis connecting the two nuclei. This bond provides a strong and stable connection. The pi bond, on the other hand, arises from the side-to-side overlap of p orbitals above and below the bonding axis. This additional bonding interaction contributes to the strength and properties of the double bond.

The presence of the sigma and pi bonds together allows the double bond to exhibit characteristics that distinguish it from single or triple bonds. In a triple bond, for example, there would be one sigma bond and two pi bonds, further increasing the bond strength and rigidity. However, in the case of a double bond, it is specifically the combination of one sigma bond and one pi bond that defines its nature.

Therefore, the correct selection accurately represents the bonding structure of a double bond.