* Atoms seek stability: Atoms are most stable when their outer electron shell (valence shell) is full. This usually means having 8 electrons (octet rule).
* Sharing electrons: Atoms with incomplete outer shells can achieve stability by sharing electrons with other atoms.
* Covalent bond formation: This shared pair of electrons forms a covalent bond, holding the two atoms together.
* Stability and molecule formation: The shared electrons are attracted to both nuclei, creating a strong electrostatic force that holds the atoms in a fixed arrangement, forming a molecule.
Example:
* A hydrogen atom (H) has one electron in its outer shell and needs one more to be stable.
* Two hydrogen atoms can share their single electrons, creating a covalent bond and forming a hydrogen molecule (H₂).
Key points:
* Covalent bonds are generally stronger than ionic bonds.
* Covalent bonds can be single, double, or triple, depending on the number of electrons shared.
* Covalent bonding is responsible for the formation of a vast array of molecules, from simple molecules like water (H₂O) to complex biological molecules like DNA.
