1. Teacher Notes for Science ATC lesson on Sept. 13,2011 Lesson Objective: 10 th grade ATC students will draw Lewis Electron Dot structures for various elements on the periodic table Lesson Objective: 10 th grade ATC students will draw Lewis Electron Dot structures for various elements on the periodic table Please have the students go over the Power Point provided. On a notebook sheet of paper, they will draw and complete the chart shown on the presentation. Please have the students go over the Power Point provided. On a notebook sheet of paper, they will draw and complete the chart shown on the presentation.

2. Science ATC Lesson for September 13, 2011 Lewis Electron Dot Structure

3. Essential Question: What is a Lewis Electron dot structure? Definition: An atom’s Lewis electron dot structure consists of the element’s symbol, which represents the atomic nucleus and inner-level electrons, surrounded by dots representing the atom’s valence electrons. Definition: An atom’s Lewis electron dot structure consists of the element’s symbol, which represents the atomic nucleus and inner-level electrons, surrounded by dots representing the atom’s valence electrons. Source: Glencoe Chemistry Matter and Change pg. 140

4. Group 1A: 1 valence electron How do we use the periodic table to draw Lewis electron dot structures? Identifying the representative group number will allow you to determine the number of valence electrons. Here’s how…. Group 2A: 2 valence electrons Group 3A: 3 valence electrons Group 4A: 4 valence electrons Group 5A: 5 valence electrons Group 6A: 6 valence electrons Group 7A: 7 valence electrons Group 8A: 8 valence electrons

5. What’s Next???? Once you have identified the group number for that element, then you know how many valence electrons it has. Once you have identified the group number for that element, then you know how many valence electrons it has. Example: Nitrogen is on group 5A, so it has 5 valence electrons. Example: Nitrogen is on group 5A, so it has 5 valence electrons. N Step 1: write the element symbol. Step 2: Start on the top of the symbol and place one electron at a time on the four sides of the symbol and then pair up until all are used.

6. Your Turn: Draw and complete a chart, such as the one you see below. Element Name Element Symbol # of valence e- Lewis Electron Dot Structure sodium calcium boron tin arsenic oxygen bromine neon

7. Remember If you have additional questions, please contact your local El Dorado Science Teacher. In addition, you may always refer to your text book: Glencoe Chemistry Matter and Change pg. 140 (Electron dot notation)