Electron Dot Diagrams / Lewis Structures Atom and Covalent Compound diagramming

Electron Dot Diagrams Shows valence electrons around an atom Valence electrons – electrons in the outermost energy level of an atom Valence electrons are only located in the outer level “s” and “p” orbitals Valence electrons are shown in the outer energy level of a “shell diagram”

Electron Shell Diagrams A shell diagram shows all electrons, but we are most interested in the electrons in the outermost energy level  called the valence level or valence shell.

Electron Dot Diagrams To draw: 1. Write chemical symbol 2. Place one dot around chemical symbol for each valence electron (up to eight dots) 3. All inner level electrons and nucleus are symbolized by the chemical symbol

Electron Dot Diagrams Line up single dots to form compounds and to make either 2 or 8 electrons around each element. The elements share their single unpaired electrons.

Electron Dot Diagrams Some electrons are already paired up within a single atom and are not shared. These are called non-bonding / unshared pairs.

Electron Dot Diagrams Some elements are able to share more than one pair of electrons to form double and triple bonds

Electron Dot Diagrams 1. Carbon 6. Hydrogen 2. Nitrogen 7. Chlorine Draw electron dot diagrams of the following elements: 1. Carbon 6. Hydrogen 2. Nitrogen 7. Chlorine 3. Phosphorus 8. Argon 4. Boron 9. Iodine 5. Oxygen 10. Helium

Homework 1. CCl4 6. H2O 2. N2O2 7. CH4 3. PBr3 8. SO2 4. BI3 9. NH3 Draw electron dot diagrams of the following compounds: 1. CCl4 6. H2O 2. N2O2 7. CH4 3. PBr3 8. SO2 4. BI3 9. NH3 5. C3H6O 10. SiO4