Bohr Diagrams are great for simple atoms, but once you start looking at how electrons are configured during chemical bonding, the Bohr Diagram starts to become cumbersome and messy.  The Lewis diagram is a variation of the Bohr model that strips out anything that is not important to show chemical bonding. While it has a number of features that are similar, it is a much cleaner way to show interactions of atoms during bonding and emphasizes what happens to the valence electrons  

Another advantage of Lewis diagrams over Bohr diagrams is that it can show what happens when there are more than one bonding pair between two atoms, and is great for explaining why atoms like Oxygen or Nitrogen can form diatomic molecues

Things you should be able to do after today:

  • determine the number of protons and electrons in ions using information from the periodic table
  • draw Lewis diagrams of ions
  • draw Lewis diagrams of ionic compounds
  • draw Lewis diagrams of covalent compounds
  • identify how many lone pairs and bonding pairs are in covalent compounds
  • identify which atoms form diatomic molecules and draw the Lewis Diagrams for them


  • Notes


  • Worksheet (we'll go over the answers in class)
  • p62-64 of your workbook


FileDescriptionFile size
Download this file (4.2c.worksheet.pdf)4.2c.worksheet.pdfLewis Diagrams Worksheet125 kB
Download this file (4.3.notes.lewis.pdf)4.3.notes.lewis.pdfNotes on Lewis Diagrams424 kB