Single Covalent Bonds
A covalent bond forms when two orbitals with one electron each overlap each other.
Upon formation of the H2 molecule, the shared electrons must have opposite spin, so they are shown with opposite spin in the atomic 1s orbital.The diatomic fluorine molecule (F2) contains a single shared pair of electrons. Each F atom also has three pair of electrons that are not shared with the other atom.
A lone pair is a pair of electrons in a Lewis electron-dot structure that is not shared between atoms. The oxygen atom in the water molecule shown below has two lone pair sets of electrons. Each F atom has three lone pairs. Combined with the two electrons in the covalent bond, each F atom follows the octet rule.
Covalent bonds form when electrons in two atoms form overlapping orbitals.
Lone pair electrons in an atom are not shared with another atom.