* Sharing of Electrons: Atoms involved in a covalent bond share one or more pairs of electrons. These shared electrons are attracted to the nuclei of both atoms, holding them together.
* Overlap of Orbitals: The shared electrons reside in overlapping atomic orbitals, which are regions of space around the nucleus where an electron is likely to be found. This overlap allows for the mutual attraction between the electrons and both nuclei.
* Electron Density: The shared electrons create a region of increased electron density between the two atoms. This increased electron density is what contributes to the strength of the covalent bond.
Types of Covalent Bonds:
* Single Covalent Bond: Involves the sharing of one pair of electrons.
* Double Covalent Bond: Involves the sharing of two pairs of electrons.
* Triple Covalent Bond: Involves the sharing of three pairs of electrons.
Important Considerations:
* Electronegativity: The tendency of an atom to attract electrons in a covalent bond. If the electronegativity difference between the two atoms is significant, the bond will be polar, with one atom having a slightly negative charge and the other a slightly positive charge.
* Valence Electrons: Only valence electrons (electrons in the outermost shell) are involved in covalent bonding.
Example:
In the formation of a water molecule (H₂O):
* Each hydrogen atom has one valence electron.
* The oxygen atom has six valence electrons.
* Oxygen shares one electron with each hydrogen atom, forming two single covalent bonds.
* The shared electrons occupy overlapping orbitals between the oxygen and hydrogen atoms.
The shared electrons create a region of high electron density between the oxygen and hydrogen atoms, holding the atoms together in the water molecule.
