The covalent bond between identical atoms is a nonpolar bond, meaning the electrons are shared equally, resulting in an electrically uniform distribution of charge.
Understanding Nonpolar Covalent Bonds
What is a Covalent Bond?
A covalent bond forms when atoms share electrons to achieve a stable electron configuration (usually an octet). This type of bond is common between nonmetal atoms.
Nonpolar Bonds Explained
In a nonpolar covalent bond, the atoms sharing the electrons have the same or very similar electronegativity. Electronegativity is a measure of an atom's ability to attract shared electrons in a chemical bond. Because the atoms have similar electronegativities, neither atom pulls the shared electrons more strongly than the other.
Examples of Nonpolar Covalent Bonds:
- Hydrogen gas (H₂): Each hydrogen atom has the same electronegativity, resulting in equal sharing of electrons.
- Oxygen gas (O₂): Similarly, both oxygen atoms have the same electronegativity.
- Diamond (C-C bonds): The carbon atoms in diamond are all identical, leading to a network of nonpolar covalent bonds.
Implications of Nonpolarity:
- Electrical Uniformity: Because the electrons are shared equally, there's no partial positive (δ+) or partial negative (δ-) charge on either atom. The molecule is electrically uniform.
- Solubility: Nonpolar molecules are generally soluble in nonpolar solvents (like dissolves like). They have weaker intermolecular forces (like van der Waals forces) compared to polar molecules.
Contrast with Polar Covalent Bonds:
In contrast to nonpolar covalent bonds, polar covalent bonds occur between atoms with significantly different electronegativities. For example, in water (H₂O), oxygen is more electronegative than hydrogen, so it pulls the shared electrons closer. This results in a partial negative charge on the oxygen atom and partial positive charges on the hydrogen atoms, making water a polar molecule.
