A o bond arises from the straight-on overlap of two atomic Sigma Bonding orbitals. The electron density lies along the axis of the two bonded nuclei. spa hybrid orbital Example: Sigma Bonding in methane, CH4 is orbital What atomic or hybrid orbitals make up the sigma bond between C2 and Cg in propylene, CH2CHCH3? (C2 Is the second carbon in the structure as written.) orbital on C2+ orbital on Es What is the approximate C-Cz-C; bond angle