Electrons in Atoms

1. Electrons in Atoms Chapter 5

2. I CAN… • Write long-hand electron configurations • Write short-hand (Nobe Gas) electron configurations • Draw s and p orbitals • Match the scientist with their contributions to the electron cloud model • Draw electron hotels! (energy level diagrams)

3. Announcements 12/10 • HW: From the PPT later on • Lab later this week, date TBA (probably on Thursday) • Grades

4. In class: Finish writing the electron configurations for each of the following: • Nitrogen – 1s2 2s2 2p3 • Chlorine – 1s2 2s2 2p6 3s2 3p5 • Sodium • Ruthenium • Gallium • Cesium • Silicon • Iodine • Vanadium

5. Check your work: • Nitrogen – 1s2 2s2 2p3 • Chlorine – 1s2 2s2 2p6 3s2 3p5 • Sodium - 1s2 2s2 2p6 3s1 • Ruthenium - 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d6 • Gallium – 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p1 • Cesium – 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s1 • Silicon – 1s2 2s2 2p6 3s2 3p2 • Iodine – 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p5 • Vanadium – 1s2 2s2 2p6 3s2 3p6 4s2 3d3

6. 8 The Octet Rule Atoms tend to gain, lose, or share electrons until they have eight valence electrons. This fills the valence shell and tends to give the atom the stability of the inert / noble gases. ONLY s- and p-orbitals are valence electrons.

7. 16 S 32.066 Core Electrons Valence Electrons Notation • Longhand Configuration S 16e- 2p6 2s2 1s2 3s2 3p4 • Shorthand Configuration S 16e- [Ne]3s2 3p4 Courtesy Christy Johannesson www.nisd.net/communicationsarts/pages/chem

8. Noble Gas Configuration • Noble Gases have their outer shell full; therefore, we can use the noble gas configuration as short hand. • Look for Noble Gas before atom you want. Sodium – has Neon before. • Ne = 1s2 2s2 2p6 • Na = 1s2 2s2 2p6 3s1 • Na = [Ne] 3s1

9. Shorthand Configuration A neon's electron configuration (1s22s22p6) B third energy level [Ne] 3s1 one electron in the s orbital C D orbital shape Na = [1s22s22p6] 3s1 electron configuration

10. Write Noble Gas Configurations for each below: • Aluminum • Bromine • Barium • Cobalt • Lead • Potassium

11. Check your work: • Aluminum – [Ne] 3s23p1 • Bromine – [Ar] 4s2 3d104p5 • Barium – [Xe] 6s2 • Cobalt – [Ar] 4s23d7 • Lead – [Xe] 6s24f145d106p2 • Potassium – [Ar] 4s1

12. Bohr Model Nucleus Electron Orbit Energy Levels

13. Bohr Model Nucleus Electron Orbit Energy Levels

14. Quantum Mechanics Werner Heisenberg ~1926 • Heisenberg Uncertainty Principle • Impossible to know both the velocity and position of an electron at the same time g Microscope Electron

15. The Electron as a Wave Schrödinger’s Wave Equation • Used to determine the probability of finding the H electron at any given distance from the nucleus • Electron best described as a cloud • Effectively covers all points at the same time (fan blades)

16. Electron Orbitals: Electron orbitals Equivalent Electron shells (a) 1s orbital (b) 2s and 2p orbitals c) Neon Ne-10: 1s, 2s and 2p 1999, Addison, Wesley, Longman, Inc.