MOLECULAR GEOMETRY

• Lewis structure of molecules - represent the arrangement of valence electron
• type of structure - molecular structure and geometric structure
• molecular structure - bond distance and bond angle
• bond distance - distance between nuclei of the two bonded atoms along a straight line joining the nuclei
• bond distance - measured in picometer or angstrom unit
• bond angle - angle between any two bonds that include a common atom
• WATER

  • molecular structure - bent or v-shape
  • bond angle - 105 degrees
• valence shell electron pair repulsion (VSEPR) theory
• VSEPR - used to predicting molecular structure formed from nonmetals
• VSEPR - structure around the atom is determined by minimizing repulsion between electron pairs
• central atom - is a molecule pivot point. the molecular formula is one which exists alone, represented by the letter A
• terminal atom - all other atoms except central atom. Represented by letter X
• lone pairs in central atoms - interaction between lone pairs and bonding pairs create repulsion
• predicting molecular geometry

  
  

  1. determine central atom
  2. Write Lewis symbol of the central atom
  3. '' '' '' terminal atom around the central atom
  4. determine AXE formula
  5. match AXE using a molecular geometry chart
• ELECTRON DENSITY AND MOLECULAR GEOMETRY

  • central atom - A
  • non-bonded electron pair - E
  • bonded pair with atom - X