1 / 13

Let’s review

Let’s review. O 8 8 8 1s 2 2s 2 2p 4. Oxygen Symbol? Atomic Number? Protons? Electrons? Electron Distribution?. Oxygen has 6 valence electrons. Episode 502. Electron Dot Diagrams. Atom’s symbol surrounded by dots to represent its valence electrons. Example Oxygen

dorjan
Télécharger la présentation

Let’s review

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Let’s review • O • 8 • 8 • 8 • 1s2 2s2 2p4 • Oxygen • Symbol? • Atomic Number? • Protons? • Electrons? • Electron Distribution? • Oxygen has 6 valence electrons. Episode 502

  2. Electron Dot Diagrams • Atom’s symbol surrounded by dots to represent its valence electrons • Example • Oxygen • 6 valence electrons • Lithium • 1 valence electron Episode 502

  3. Problem Set 1 Draw the Electron Dot Diagrams for: Magnesium Helium Krypton Aluminum Bromine Potassium Nitrogen Silicon Strontium Episode 502

  4. Lewis Structure • Diagram representing the arrangement of valence electrons in a molecule • Most atoms need 8 valence electrons to become stable. The exceptions are H and He which need 2 valence electrons to be stable. Episode 502

  5. Lewis Structure for H2 • 2 electrons belonging to both atoms • Represented by a dash between the symbols • H - H • Shared pair Episode 502

  6. Lewis Structure for Cl2 • Each Cl atom has 7 valence electrons; giving a total of 14 valence electrons to work with. • Shared pair • Unshared pair • Electrons belonging to only one atom • Represented by 2 dots Episode 502

  7. Lewis Structure for HCl H - Cl Episode 502

  8. When more than two atoms bond, you must determine which is central. • The central atom is: • Frequently carbon • Never hydrogen • Often atom with the smallestelectronegativity H • Lewis structure for CH3I • (Thereare a total of 14 valence electrons to work with.) H C I H Episode 502

  9. Problem Set 2 NH3 CH2Cl2 CH3OH (a little tricky) C6H12 (Hint: The carbon atoms form a ring.) Episode 502

  10. Lewis structure of ethene, C2H4 • (has total of 12 valence electrons) H H C C H H Single bond 1 Double bond 2 Triple bond 3 Episode 502

  11. Problem Set 3 CO2 HCN CH2O C2HCl Episode 502

  12. Polyatomic Ion • Covalently bonded groups of ions with a charge NO3-1 Has gained 1 electron to give a total of 24 valence electrons to work with • N = 5 electrons • O = 3 x 6electrons = 18 electrons • -1 = 1 extra electron • [ ]-1 O N O O Episode 502

  13. Problem Set 4 PO4-3 SO4-2 NH4+1 CN-1 Episode 502

More Related