1. VALENCE ELECTRONS 2-8-8 Rule for Electrons 1 st Ring = Max 2 Electrons 2 nd Ring = Max 8 Electrons 3 rd Ring = Max 8 Electrons

2. Valence Electrons Recall … Electrons in the outermost energy level (shell, orbit, rings) VALENCE ELECTRONS are called VALENCE ELECTRONS Ex. 16 electrons: 2-8-6 This element has 6 valence electrons. # electrons = # protons (Atomic Number) The valence shell

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11. Main Group Valence shells Grp 1 2 13 14 15 16 17 18 As we move from left to right we add one electron at a time To the outermost energy level – the Valence shell 1e 2e 3e 4e 5e 6e 7e 8e

12. Electron Dot Diagrams (Lewis Structures) To draw: 1. Write chemical symbol 2. Place one dot around chemical symbol for each valence electron (up to eight dots)

13. Lewis dot Structures for the atoms of groups 1-2 and 13-18 of The periodic table The Main group elements Notice the valence electron trends