Distinguishing Polar and Nonpolar Molecules

Key Concepts

• Polar Molecules: Molecules with a net dipole moment due to differences in electronegativity, leading to an uneven distribution of charge.
• Nonpolar Molecules: Molecules without a net dipole moment, often due to symmetry or having atoms with similar electronegativity.

Identifying Nonpolar Molecules

1. Single Element Molecules:

   • Monoatomic or diatomic molecules composed of a single element are nonpolar.
   • Examples:
     • Diatomic molecules: N₂, O₂, Cl₂, F₂, H₂
     • Monatomic noble gases: Helium, Neon, Argon, Xenon

2. Molecules with Only Carbon and Hydrogen:

   • Hydrocarbons composed solely of carbon and hydrogen are nonpolar.
   • Examples:
     • Methane (CH₄)
     • Alkanes like Ethane (C₂H₆)
     • Ethene (CH₂=CH₂), which contains a double bond but is still nonpolar due to symmetry and uniform distribution of electronegativity.