What forms a single covalent bond?

1 Answer
Sep 12, 2016

The overlap or sharing of two electron orbitals.


Covalent bonds involve the sharing of electrons to create bonds.
The prefix Co indicates the idea of sharing cooperate, community, corporation.

For atoms to share electrons the electonegativities of the two atoms must be similar. If the electronegativities of the two atoms are too different an ionic bond will be formed instead of a covalent bond.
as in #NaCl#

Carbon and Hydrogen form covalent bonds because the electronegativity of C is 2.5 while Hydrogen is 2.1. Because the pull of on the electrons ( electronegativity) is about equal the bonds will be covalent.

Hydrogen has only 1 electron it needs 2 to be stable. Carbon needs 4 electrons needs 4 electrons to be stable. Each of 4 Hydrogen atoms shares its one electron with Carbon providing Carbon with the four extra electrons it needs to be stable. In return the Carbon shares four electrons one to each of 4 Hydrogen atom allowing Hydrogen to be stable.

In a covalent bond the valance electrons of two atoms share an orbital made from the overlap of orbitals from two different atoms. As the electrons move in this new electron cloud the electrons are attracted to different atoms forming the covalent bond.