1. AS 020 09-Jul-12

2. BASIC IDEAS Shapes of molecules and ions depends on total number of electron pairs around the central atom. Two types of electron pairs: Bonding pairs (i.e. e - ’s in a covalent bond) Non-bonding pairs (i.e. lone pairs) These electron pairs repel as far as possible (but lone pairs repel more than bonding pairs).

3. https://people.ok.ubc.ca/wsmcneil/vsepr.htm Very useful website (all rotateable)

4. 2 ELECTRON PAIRS electron pairs bonding pairs lone pairsshape 220linear

5. 2 bonding pairs linear

6. 3 ELECTRON PAIRS electron pairs bonding pairs lone pairsshape 330Trigonal planar 321Bent (V-shape)

7. 3 bonding pairs Trigonal planar

8. 2 bonding pair + 1 lone pair Bent

11. 4 electron pairs tetrahedral

13. 3 electron pairs + 1 lone pair trigonal pyramid

15. 2 bonding pairs + 2 lone pairs bent

16. 4 ELECTRON PAIRS electron pairs bonding pairs lone pairsshape 440Tetrahedral 431Pyramidal 422Bent (V-shape)

17. 5 ELECTRON PAIRS electron pairs bonding pairs lone pairsshape 550 Trigonal bipyramidal 541 532 Trigonal planar or T-shape

18. 5 electron pairs Trigonal bipyramidal

19. 4 bonding pairs + 1 lone pair Seesaw

20. 3 bonding pairs + 2 lone pairs T-shape

21. 6 ELECTRON PAIRS electron pairs bonding pairs lone pairsshape 660Octahedral 651 Distorted square pyramid 642Square planar

22. 6 electron pairs octahedral

23. 5 bonding pairs + 1 lone pairs square pyramid

24. 4 bonding pairs + 2 lone pairs square planar

26. http://www.lsbu.ac.uk/php-cgiwrap/biology/pfpb.php3?page=http://www.lsbu.ac.uk/biology/biolchem/shapes.html