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ChemLive. Lesson 3.06 Covalent Bonding and Lewis Structures. Lesson 3.06 Covalent Bonding and Lewis Structures. What do you already know?. What are you here to learn?. Have your paper, pencil, calculator, and Periodic Table ready. . . Objectives.
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ChemLive Lesson 3.06 Covalent Bonding and Lewis Structures
Lesson 3.06 Covalent Bonding and Lewis Structures • What do you already know? • What are you here to learn? Have your paper, pencil, calculator, and Periodic Table ready. . .
Objectives • After completing this lesson, you will be able to: • Determine how atoms will covalently bond together based on location on the periodic table. • Draw Lewis structures to model covalently bonded molecules.
Valence Electrons • How many valence electrons?
Covalent Bonding • Nonmetals share electrons to complete an octet (or duet): • Oxygen needs 2 for an octet • Hydrogen need 1 for a duet
Covalent Bonding • How many bonds are formed?
Multiple Bonds • If more electrons are needed, multiple pairs can be shared. • Oxygen shares two pairs for a double bond
Multiple Bonds • Multiple bonds are stronger and shorter:
Review • Ionic bonds exist as formula units – electrons are transferred (Na+ or O2-) between a metal and a nonmetal • Covalent bonds form molecules – electrons are shared (NO2) between nonmetals • Polyatomic ions are groups of covalently bonded atoms with an ionic charge (CO32-)
Lewis Structures • Steps • 1. Least electronegative element in the center • 2. Calculate total valence electrons • 3. Write skeleton structure • 4. Complete valence electrons • 5. Compare totals • 6. Distribute electrons
Lewis Structures • CO2 • 1. C • 2. 4 + 2(6) = 16 • 3. • 4. erase 4 around C • 5. 20 – 4 = 16 move electrons to • 6. form double bonds
Lewis Structures • HCN • 1. C • 2. 1 + 4 + 5 = 10 • 3. • 4. erase 4 around C • 5. 14 – 4 = 10 move electrons to • 6. form a triple bond
Lewis Structures • NH4+ • 1. N • 2. 5 + 4(1) -1 = 8 • 3. • 4. done • 5. 8
Lewis Structures • H2O • 1. • 2. • 3. • 4. • 5. • 6.
Lewis Structures • NH3 • 1. • 2. • 3. • 4. • 5. • 6.
Lewis Structures • CH4 • 1. • 2. • 3. • 4. • 5. • 6.
Submit Educator students Blackboard students: Virtual Lab or hands-on lab
3.06B Intermolecular Forces Educator: Submit into 4.12 Blackboard: Do the virtual lab or this one
Submit Educator: Submit into 4.12. Blackboard: if doing hands-on lab, submit into 3.06