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Intramolecular vs. Intermolecular Forces

Jul 15, 2025

Overview

This lecture explains the difference between intramolecular and intermolecular forces, focusing on their definitions, where they occur, and why the distinction matters in chemistry.

Intramolecular Forces

  • Intramolecular forces are forces that exist within a molecule, holding its atoms together.
  • These forces are the same as chemical bonds (e.g., ionic, covalent, and metallic bonds).
  • Intramolecular forces involve the sharing or transfer of electrons between atoms within one molecule.

Intermolecular Forces

  • Intermolecular forces are forces that exist between two or more separate molecules.
  • These forces attract molecules to each other but do not create chemical bonds.
  • Intermolecular forces result from regions of opposite charge attracting each other; no sharing or transfer of electrons occurs.

Key Difference: Intra vs. Inter

  • The key difference is location: intramolecular forces occur within a single molecule, while intermolecular forces occur between different molecules.
  • "Intra-" means "within" or "inside"; "inter-" means "between" or "among."

Key Terms & Definitions

  • Intramolecular Force — force or bond holding atoms together within a single molecule.
  • Intermolecular Force — attraction between two or more separate molecules; not a bond.
  • Bond — a stable association between atoms involving electron sharing or transfer.
  • Ionic Bond — bond formed by the transfer of electrons.
  • Covalent Bond — bond formed by the sharing of electrons.
  • Metallic Bond — bond involving delocalized electrons among metal atoms.

Action Items / Next Steps

  • Review the definitions and examples of ionic, covalent, and metallic bonds.
  • Understand the distinction by identifying intramolecular and intermolecular forces in sample molecules.
  • Watch further videos on bonding and intermolecular forces for deeper understanding.