Lewis Structures = Dot Diagrams We can show how the atoms share or transfer electrons by drawing electron dot diagrams. You will only use the valence e- for dot diagrams.

Dot Diagrams Start the dot diagram by writing the atomic symbol for the atom. Ex: Mg The symbol has 4 sides…

Dot Diagrams Mg Each side can hold up to 2e- for a maximum of 8e-. You cannot pair the electrons until there is one on each side.

Dot Diagrams Mg Mg only has 2 valence e-. So its dot diagram looks like this: Mg

Dot Diagrams Lets Practice!!! Draw the Dot Diagrams for: 1.) Cl 4.) C 2.) Al 5.) Ne 3.) Na

Dot Diagrams How did you do??? 1. Cl 4.) C 2.) Al 5.) Ne 3.) Na

Dot Diagrams Now we can put individual diagrams together to show whether atoms transfer (ionic bonds) or share (covalent bonds) their valence e-!!!

Bonding Dot Diagram Steps 1.) Identify the type of bond you have. (Covalent or Ionic) 2.) Separate the individual elements and put them in a line or box formation. Put the atomic symbol w/ least amount of valence e- in CENTER!!! (Remember H’s have to be on ENDS!!!) 3.) Draw the “dots” for each atomic symbol. 4.) Locate all of the “lonely e-”. Show either the transferring or sharing of e- with arrows or bars. (If sharing…connect the “lonely” dots between DIFFERENT symbols!!!) 5.) For COVALENT: Count the e- around each atomic symbol to make sure there are 8!!! (ONLY 2 for H!!!)

Dot Diagrams for Ionic Bonds We know that in an Ionic Bond (metal +nonmetal) atoms are transferring their valence e- … We can show this w/ dot diagrams. For Ex: (Li + Cl = LiCl) Li Cl

Dot Diagrams for Covalent Bonds We know that in a Covalent Bond (nonmetal + nonmetals) atoms are sharing their valence e- … We use a BAR written between the Atomic Symbols to represent the sharing of e-. One bar = 2 e- For Ex: H 2 O

Dot Diagrams for Covalent Bonds One bar = 2 e-. For Ex: H 2 O H O H ***H’s ALWAYS have to go on the ENDS.

Dot Diagram Practice 1.) CaCl 2 2.) SiO 2 3.) NH 3 4.) Na 3 N