1. Aim: To learn to draw a Lewis Structure Watch the videos Video: Introduction to Chemical Bonding Video: Covalent Bonding as taught be a water drop! Video: Particle Theory of Matter (Song) Tuesday, 23 February 2016

2. Aim: To learn to draw a Lewis Structure Copy the notes below Lewis Structures – Shows the valence electrons in a covalent molecule (one with shared electrons) – Electrons are in pairs Bonding pairs Non-bonding pairs Tuesday, 23 February 2016

3. Aim: To learn to draw a Lewis Structure Copy the notes below Steps for drawing a Lewis Structure – Count up the number of valence electrons H has 1, others have their group number – 10 – Draw the atom symbols with the single atom in the centre – Put a pair of electrons between each atom – Put electrons around the out atoms to complete their outer shells; H needs 2, others need 8. – Put any extra electrons around the central atom – Share electrons from outer atoms with central atom (if required) to make 8. Tuesday, 23 February 2016

4. Aim: To learn to draw a Lewis Structure Watch the demonstration of drawing a Lewis Structure Methane (Natural Gas) Number of bonding electrons = 4+1+1+1+1 = 8 Tuesday, 23 February 2016

5. Aim: To learn to draw a Lewis Structure Watch the demonstration of drawing a Lewis Structure Put a pair of electrons between each H and the C atom to join them Tuesday, 23 February 2016

6. Draw the Lewis Structure of: Make sure each hydrogen has 2 electrons around it and the carbon atom has 8 electrons Tuesday, 23 February 2016

7. Aim: To learn to draw a Lewis Structure Try to draw the Lewis structures of the molecules below; then watch the videos to see if you did it right NH 3 and H 2 CO Drawing the Lewis Structure of ammonia Video on H2CO Tuesday, 23 February 2016

8. Aim: To learn to draw a Lewis Structure Watch the demonstration of drawing a Lewis Structure There are 5+1+1+1 = 8 electrons When 6 have been used to join atoms put the other two on the central atom Tuesday, 23 February 2016

9. Aim: To learn to draw a Lewis Structure Watch the demonstration of drawing a Lewis Structure 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 Tuesday, 23 February 2016

10. Aim: To learn to draw a Lewis Structure Watch the demonstration of drawing a Lewis Structure 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”. Tuesday, 23 February 2016

11. Aim: To learn to draw a Lewis Structure Draw these Lewis Structures test yourself Water H 2 O Carbon Dioxide CO 2 Ethyne HCCH (has two central atoms) Carbon Monoxide CO Tuesday, 23 February 2016

12. Aim: To learn to draw a Lewis Structure Check your Lewis Structures Tuesday, 23 February 2016

13. Aim: To learn to draw a Lewis Structure Check your Lewis Structures Tuesday, 23 February 2016

14. Aim: To learn to draw a Lewis Structure Check your Lewis Structures Tuesday, 23 February 2016

15. Aim: To learn to draw a Lewis Structure Check your Lewis Structures 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) Tuesday, 23 February 2016

16. Ethyne HCCH Share electrons between C atoms Tuesday, 23 February 2016

17. Aim: To learn to draw a Lewis Structure Check your Lewis Structures Tuesday, 23 February 2016

18. Aim: To learn to draw a Lewis Structure Check your Lewis Structures Tuesday, 23 February 2016

19. Aim: To learn to draw a Lewis Structure Check your Lewis Structures Tuesday, 23 February 2016

20. Aim: To learn to draw a Lewis Structure Check your Lewis Structures Tuesday, 23 February 2016