Sigma Bonding bond arises from the straight-on overlap of two atomic orbitals. The electron density lies along the axis of the two bonded nuclei. sp3 hybrid orbitals Example: Sigma Bonding in methane; CH4 Is orbital What atomic or hybrid orbitals make up the sigma bond between C2 and (C2 is the second carbon in the structure as written) tetrafluoroethylene; C2F4 orbital on C2 orbital on F What is the approximate C1-C2-F bond angle?