COVALENT BONDING

bond length: single < double < triple
bond strength: single < double < triple
use VSEPR to predict the shapes of molecules
1. pairs of valence electrons repel each other and will take up positions to minimise these repulsions
2. lone pairs repel more than bonding pairs
giant covalent compounds
1. have high melting points because covalent bonds are broken when melting
2. Examples
  1. silicon
  2. SiO2
  3. diamond
  4. graphite
covalent molecular compounds
1. non-polar molecules
2. polar molecules
  1. difference in electronegativity: electrons lie more towards one atom than another
  2. shape of molecules: if the dipole moments of individual bonds cancel, the molecule is not polar
3. only intermolecular forces are broken when melting
  1. Van der Waals forces caused by instantaneous and induced dipoles
  2. dipole-dipole forces
  3. hydrogen bonds

Resource summary

	Created by CrazyFreeMind over 9 years ago