Intramolecular forces

• Intramolecular forces are forces within a molecule
• Ionic bonding is the electrostatic attraction between positive (cations) and negative (anions) ions in an ionic crystal lattice
  • These ions are formed by transferring the electrons from one species to the other
• Covalent bonds are formed when the outer electrons of two atoms are shared
• Metallic bonding is the electrostatic attraction of positively charged metal ions and their delocalised electrons in a metal lattice

Intramolecular forces

Intermolecular forces

• Intermolecular forces are forces between molecules and are also called van der Waals’ forces
• Permanent dipole – permanent dipole are the attractive forces between two neighbouring molecules with a permanent dipole
• Hydrogen bonds are a special type of permanent dipole – permanent dipole forces
• Instantaneous dipole – induced dipole (London dispersion) forces are the attractive forces between a temporary dipole and a neighbouring molecule with an induced dipole

Intermolecular forces

• In general, the intramolecular forces are stronger than intermolecular forces
• The strengths of the types of bond or force are as follows:

The varying strengths of different types of bonds