* Electronegativity: Nonmetals have a higher electronegativity than metals. This means they have a stronger attraction for electrons.
* Sharing Electrons: In a covalent bond, atoms share electrons to achieve a stable electron configuration (usually a full outer shell). Since nonmetals are close to having a full outer shell, they readily share electrons.
* Types of Covalent Bonds:
* Pure Covalent Bonds: These occur between atoms of the same element (e.g., O2, H2, Cl2).
* Polar Covalent Bonds: These occur between atoms of different elements where the electrons are shared unequally (e.g., H2O, CO2).
Examples of Covalent Bonding:
* H2O (Water): Hydrogen (nonmetal) and Oxygen (nonmetal) share electrons.
* CO2 (Carbon Dioxide): Carbon (nonmetal) and Oxygen (nonmetal) share electrons.
* NH3 (Ammonia): Nitrogen (nonmetal) and Hydrogen (nonmetal) share electrons.
* CH4 (Methane): Carbon (nonmetal) and Hydrogen (nonmetal) share electrons.
Exceptions:
While most covalent bonds involve nonmetals, there are a few exceptions:
* Metallic Bonds: These involve the sharing of electrons between metal atoms.
* Some Metal-Nonmetal Bonds: In some cases, a metal and a nonmetal can form a covalent bond, such as in aluminum chloride (AlCl3).
Key Takeaway: Covalent bonding is a powerful force that holds atoms together in molecules and is most common between nonmetals due to their shared tendency to gain electrons.
