Lewis Dot Diagrams
description
Transcript of Lewis Dot Diagrams
![Page 1: Lewis Dot Diagrams](https://reader035.fdocuments.net/reader035/viewer/2022081800/568142e5550346895daf4458/html5/thumbnails/1.jpg)
Lewis Dot DiagramsLewis Dot Diagrams
• Show where electrons and bonds exist in covalent compounds.
[http://www.bbc.co.uk/schools/gcsebitesize/img/gcsechem_54.gif]
![Page 2: Lewis Dot Diagrams](https://reader035.fdocuments.net/reader035/viewer/2022081800/568142e5550346895daf4458/html5/thumbnails/2.jpg)
Lewis Dot DiagramsLewis Dot Diagrams
• Dots are used to show valence electrons for specific atoms.
[http://wps.prenhall.com/wps/media/objects/476/488316/Instructor_Resources/Chapter_10/FG10_00-02.2un.JPG]
![Page 3: Lewis Dot Diagrams](https://reader035.fdocuments.net/reader035/viewer/2022081800/568142e5550346895daf4458/html5/thumbnails/3.jpg)
Lewis Dot DiagramsLewis Dot Diagrams
• Electrons are “shared” to form bonds and satisfy the octet rule.
• Example: H2O
[http://wps.prenhall.com/wps/media/objects/476/488316/Instructor_Resources/Chapter_10/FG10_00-19un.JPG]
![Page 4: Lewis Dot Diagrams](https://reader035.fdocuments.net/reader035/viewer/2022081800/568142e5550346895daf4458/html5/thumbnails/4.jpg)
Lewis Dot DiagramsLewis Dot Diagrams
• Example: NH3
• 1st – Count up all valence electrons
• N = 5 e-
• H = 1 e- x 3 = 3 e-
• 8 total valence electrons
![Page 5: Lewis Dot Diagrams](https://reader035.fdocuments.net/reader035/viewer/2022081800/568142e5550346895daf4458/html5/thumbnails/5.jpg)
Lewis Dot DiagramsLewis Dot Diagrams
• 2nd – Draw individual dot diagrams
• Hint – place 1 per side to start.
N
HH H
![Page 6: Lewis Dot Diagrams](https://reader035.fdocuments.net/reader035/viewer/2022081800/568142e5550346895daf4458/html5/thumbnails/6.jpg)
Lewis Dot DiagramsLewis Dot Diagrams
• 3rd – Connect lone electrons to satisfy octet rule and form “bonds”
• Remember, H only wants 2 e- !
N
HH H
![Page 7: Lewis Dot Diagrams](https://reader035.fdocuments.net/reader035/viewer/2022081800/568142e5550346895daf4458/html5/thumbnails/7.jpg)
Lewis Dot DiagramsLewis Dot Diagrams
• Last Step – Draw a “final” picture with lines (2 shared electrons)
• Make sure that all valence electrons are accounted for!
• Any electrons that are not in bonds are called unshared, or lone pairs.
[http://wps.prenhall.com/wps/media/objects/476/488316/Instructor_Resources/Chapter_10/FG10_00-71un.JPG]
8 Total Electrons!
![Page 8: Lewis Dot Diagrams](https://reader035.fdocuments.net/reader035/viewer/2022081800/568142e5550346895daf4458/html5/thumbnails/8.jpg)
Lewis Dot DiagramsLewis Dot Diagrams
• Some compounds will share more than 2 electrons, so multiple bonds are drawn.
• Example: O2
![Page 9: Lewis Dot Diagrams](https://reader035.fdocuments.net/reader035/viewer/2022081800/568142e5550346895daf4458/html5/thumbnails/9.jpg)
![Page 10: Lewis Dot Diagrams](https://reader035.fdocuments.net/reader035/viewer/2022081800/568142e5550346895daf4458/html5/thumbnails/10.jpg)
Each O has 8 e-
Double Bond
![Page 11: Lewis Dot Diagrams](https://reader035.fdocuments.net/reader035/viewer/2022081800/568142e5550346895daf4458/html5/thumbnails/11.jpg)
Lewis Dot DiagramsLewis Dot Diagrams
• Exceptions to the Octet Rule:
• Boron (6 e-)
[http://wps.prenhall.com/wps/media/objects/476/488316/Instructor_Resources/Chapter_10/FG10_00-46un.JPG]
![Page 12: Lewis Dot Diagrams](https://reader035.fdocuments.net/reader035/viewer/2022081800/568142e5550346895daf4458/html5/thumbnails/12.jpg)
Lewis Dot DiagramsLewis Dot Diagrams
• Phosphorus (10 e-)
• Sulfur (12 e-)
[http://wps.prenhall.com/wps/media/objects/476/488316/Instructor_Resources/Chapter_10/FG10_00-46un.JPG]
![Page 13: Lewis Dot Diagrams](https://reader035.fdocuments.net/reader035/viewer/2022081800/568142e5550346895daf4458/html5/thumbnails/13.jpg)
Lewis Dot DiagramsLewis Dot Diagrams
Too many valence electrons
Si not stable
Center H has too many e-
N not stable
What is wrong in the following diagrams?