Drawing Lewis Structures

1. Drawing Lewis Structures Testing Time

2. Draw the Lewis Structure of: • Methane (Natural Gas) • CH4

3. Draw the Lewis Structure of: • Methane (Natural Gas) • Number of bonding electrons = 4+1+1+1+1 = 8 H H C H H

4. Draw the Lewis Structure of: Put a pair of electrons between each H and the C atom to join them H H C H H

5. Draw the Lewis Structure of: Make sure each hydrogen has 2 electrons around it and the carbon atom has 8 electrons H H C H H

6. Draw the Lewis Structures of NH3 and H2CO

7. NH3 ammonia a smelly but useful gas There are 5+1+1+1 = 8 electrons When 6 have been used to join atoms put the other two on the central atom H H N H

8. H2CO methanal a smelly gas used by be a disinfectant (germ killer) There are 1+1+4+6 = 12 electrons When 6 have been used to join atoms put the other two on the oxygen atom – to give it 8 H O C H

9. The C atom only has 6 electrons around it – it wants 8; so the oxygen atom shares 2 with the carbon atom. This makes a “double bond”. H O C H

10. Home Work • Draw the Lewis Diagram for • Water H2O • Carbon Dioxide CO2 • Ethyne HCCH • Carbon Monoxide CO

11. Water H2O H O H

12. Carbon Dioxide CO2 O C O

13. Carbon Dioxide CO2 O C O

14. Ethyne HCCH Count up the electrons in outer shells Put a pair of electrons between each atom Move the rest to the C atoms (Hs have enough) H C C H

15. Ethyne HCCH Share electrons between C atoms H C C H

16. Ethyne HCCH H C C H

17. Carbon Monoxide CO C O

18. Carbon Monoxide CO C O

19. Carbon Monoxide CO C O