Aka Dot Diagrams Electron Dot Diagrams Lewis Dot Structures Aka Dot Diagrams Electron Dot Diagrams

Valence electrons are the electrons on the outermost energy level. 6 valence electrons on this atom. Review - Students know this already Image from Wikipedia

     1s 2s 2p Valence electrons The final s and p valence electrons are especially important because they determine what kinds of reactions an atom will undergo. Have a student read this out loud

Example: Tin, Sn: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p2 If you write the Shorthand Configuration for an element, the s and p electrons on the highest energy level are the valence electrons. Example: Tin, Sn: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p2 Have a student read this out loud. The arrow and boxes animate in on a mouse click. valence electrons

Lewis Dot Structures show only the Valence electrons for an element. A Dot Diagram consists of two parts: the element symbol dots that represent the S and P block electrons Dots may only go on the sides of the element symbol Sn Have a student read this out loud, Each bullet animates in on a mouse click.

Rules for Writing Lewis Dot Diagrams: Only use s and p valence electrons If there are d or f valence electrons in between the s and p sublevels, they are left out of the dot diagram. Have a student read this out loud. The no symbol animates in on mouse click. 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p2

Rules for Writing Lewis Dot Diagrams: You must put 1 electron dot on each side of the element symbol before you put 2 on one side (like Hund’s rule) El El Have a student read this out loud. The element symbol comes in on mouse click and the dots and no sign come in automatically 1 second apart. For example: Imaginary Elementium (El) has 3 valence electrons (5s2 and 5p1)

Finding the Valence Electrons Use electron configuration to begin filling in the energy levels. When done, count the electrons in the outer shell. **OR, remember the shortcut. The group number of a main group element (A) tells us the number of valence electrons. Group 1 has 1 valence electron, Group 2 has 2 valence electrons.….etc.

Sn Example: Tin, the last electrons are 5s2 4d10 5p2. For the dot diagram, we will use only the valence electrons 5s2 and 5p2. Therefore we will place 4 dots around the element symbol. Sn Have a student read this out loud. The dots and squares com in on mouse clicks. = places where electrons can go Don’t draw it, just think it

A total of 7 electron dots. Example: Bromine Shorthand Configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5. Use only the 4s2 and the 4p5. A total of 7 electron dots. Have a student read this out loud. Dots come in automatically after 1 mouse click. Br

Practice problems Neon Sodium Aluminum Give them some time to practice – maybe 3 minutes. Then show them the answers on the next slide

Ne Na Al Answers to Practice No, it does not matter which side has no electron dots as long as there are the correct number of sides without dots. Show them answers for a few seconds before showing them the assignment slide. Al

Exit Ticket Write two goals you have 1 Academic 1 Personal Give at least two ways you will work toward achieving each goal