Final answer:
Valence bond theory explains the bonding in O2 with one σ bond resulting from head-on overlap of 2p orbitals, and two π bonds from sideways overlap of 2p orbitals. There is not a σ bond from 2s or a π bond from 2s involved in the bonding of O2.
Step-by-step explanation:
According to the valence bond theory, the bonding in diatomic oxygen (O2) involves the overlap of atomic orbitals. The molecule has both σ and π bonds, created by different types of overlaps.
- a) The σ bond formed by head-on overlap of 2p orbitals occurs along an axis containing the nuclei, creating an area where the two atoms share electrons.
- b) Another σ bond can be formed by the head-on overlap of 2s orbitals, although in O2, this is not the case since its σ bonds involve 2p orbitals.
- c) The π bonds result from the sideways overlap of 2p orbitals, creating regions above and below the axis containing the nuclei where the electrons are shared.
- d) The overlap of 2s orbitals would not typically create a π bond due to their spherical shape; π bonds are typically formed between p orbitals or between hybrid orbitals that have the appropriate orientation.
In the case of O2, there are two π bonds formed by the sideways overlap of two pairs of 2p orbitals. This is consistent with the electronic configuration of oxygen, which has two unpaired electrons in 2p orbitals that are available for bonding.