Hydrogen does not follow the traditional octet rule; instead, it follows the duet rule, achieving stability by having two electrons in its valence shell.
The "octet rule" states that atoms are most stable when surrounded by eight valence electrons. This configuration is similar to that of the noble gases, which are known for their lack of reactivity. However, hydrogen, being a small atom with only one electron, only needs to achieve the electron configuration of helium (another noble gas) to become stable. Helium has two electrons.
Therefore, hydrogen achieves stability by:
- Sharing Electrons: Hydrogen typically forms covalent bonds with other atoms (including other hydrogen atoms). When two hydrogen atoms bond, they share their single electron, creating a stable diatomic molecule (Hâ‚‚). In this molecule, each hydrogen atom effectively "has" two electrons, fulfilling its "duet" rule.
- Ionic Bonding: Hydrogen can also lose its single electron to form a H+ ion, or gain an electron to form a H- ion. However, covalent bonding is a much more common occurrence.
In summary, hydrogen's version of the octet rule is the "duet rule," where it aims to have two electrons in its valence shell, resembling the electronic configuration of helium. This is typically achieved through sharing electrons in covalent bonds.
