Electrons What are they and where are they? Agenda: Review Brain Break Crash Course - Electrons Brain Break Electron Configuration Practice Brain Break Octet Rule, Nobel Gas Configuration A Few Last Things Review Electrons • Found outside the nucleus • Extremely small • Negative charge Protons and Electrons Electron Orbitals Opposites Attract Electrons repel electrons Protons repel protons Protons and electrons attract each other How big are electrons, neutrons, and protons? More about Electrons ptable.com Here are a few problems… • Identify how many electrons a neutral atom would have. • Nitrogen? • Magnesium • Oxygen? • Xenon? • Carbon? Ready for the Answers? Were you right? • Identify how many electrons a neutral atom would have. • Nitrogen - 7 • Magnesium - 12 • Oxygen - 8 • Xenon - 54 • Carbon - 6 Time for a Brain Break! Electron Configuration Video Time for a Brain Break! Electron Placement Electron Placement Electron Placement Electron Placement Aufbau and Electron Orbitals • • Aufbau (German for “to build”) - electrons want the lowest possible placement Pauli’s exclusion principle - no two electrons can exist in the same space Electron Shells Here are a few problems… • Determine the electron configuration for the neutral atom • Nitrogen - • Magnesium - • Oxygen - • Xenon - • Carbon - • Iron - Ready for the Answers? Were you right? • Determine the electron configuration for the neutral atom • Nitrogen - 1s22s22p3 • Magnesium - 1s22s22p63s2 • Oxygen - 1s22s22p4 • Xenon - 1s22s22p63s23p64s23d104p65s24d105p6 • Carbon - 1s22s22p2 • Iron - 1s22s22p63s23p64s23d6 Time for a Brain Break! The Octet Rule • Electrons want to have eight electrons in their outer shells. Why? • C, N, O, and F always obey this rule. • WATCH OUT! There are exceptions • • Notable - H Why is this important? Electron Placement Nobel Gas Configuration Another (easier?) way to write electron configuration An example Write the electron configuration for sulfur using both the full notation and nobel gas configuration One more example Write the electron configuration for silver using both the full notation and nobel gas configuration Here are a few problems… • Determine the electron configuration for the neutral atom • Nitrogen - • Magnesium - • Oxygen - • Xenon - • Carbon - • Iron - Ready for the Answers? Were you right? • Determine the electron configuration for the neutral atom • Nitrogen - [He]2s22p3 • Magnesium - [Ne]3s2 • Oxygen - [He]2s22p4 • Xenon - [Kr]5s24d105p6 • Carbon - [He]2s22p2 • Iron - [Ar]4s23d6 A Few More Things Ions ptable.com Here are a few problems… • • What type of ion (charge and cation/anion/neutral species would the following elements make? • Sodium • Chlorine • Oxygen • Nitrogen • Neon Can you notice any patterns between where an element is located on the periodic table and it’s likelihood to loose/gain electrons? Ready for the Answers? Were you right? • • What type of ion would the following elements make? • Sodium - Cation, Na+ • Chlorine - Anion, Cl- • Oxygen - Anion, O2- • Nitrogen - Anion, N3- Can you notice any patterns between where an element is located on the periodic table and it’s likelihood to loose/gain electrons? Lewis Dot Structures Lewis Dot Structures Here’s an example: Draw the Lewis dot structure for oxygen What about for Krypton? Sodium? Here are a few problems… • • Draw the Lewis dot structure for the following elements • Potassium • Chlorine • Nitrogen • Neon Can you notice any patterns between where an element is located on the periodic table and it’s Lewis dot structure? Ready for the Answers? Were you right? • • Draw the Lewis dot structure for the following elements • Potassium • Chlorine • Nitrogen • Neon Can you notice any patterns between where an element is located on the periodic table and it’s Lewis dot structure? On your own… • Complete the Protons, Neutrons, and Electrons worksheet • Complete the Electron Configuration worksheet • Complete the Lewis Dot Structure worksheet • Practice identifying electron configurations https://www.khanacademy.org/science/chemistry/electroni c-structure-of-atoms/electron-configurations-jaysal/e/electron-configurations-exercise?modal=1 • What are 3 things you’ve 3 • 2 • 1 learned? What are 2 things you want to learn more about? What’s one question you still have? Resources • • • • Periodic Table - https://www.ptable.com Phet Build an Atom https://phet.colorado.edu/en/simulation/build-an-atom Review of Electron Configuration https://www.chem.fsu.edu/chemlab/chm1045/e_config.htm l Practice Identifying Electron Configurations https://www.khanacademy.org/science/chemistry/electroni c-structure-of-atoms/electron-configurations-jaysal/e/electron-configurations-exercise?modal=1
