1. Quantum-Mechanical Model pg. 294-301 LO: I can write the electron configuration of elements in the PT.

2. What is the quantum-mechanical model? A model that explains... The probability of where an electron exists when orbiting the nucleus. With a focus on... The energy of the electrons

3. Bohr Model vs. Quantum-Mechanical Model Bohr Orbits—circular path around the nucleus showing the electrons motion.  Differently sized radii Quantum-Mechanical Orbitals—probability map showing likelihood of where an electron will be found.  Differently sized shapes

4. Quantum Numbers Used to specify an electron’s “address” 4 total numbers 1.Energy level “n” 2.Sublevel “shape” 3.Orientation of sublevel orbitals 4.Spin of electrons in sublevel orbitals “m s ”

5. QN1: Energy Levels 1.Energy level “n”  n = 1, 2, 3, 4, 5, 6, 7  The higher the number, the farther the e - is from the nucleus.

6. QN2: Sublevel Shape 2.Sublevel “shape”  s = spherical  p = lobed  d = dumbbell  f = “complicated” There are as many sublevels as the number of the level.

7. QN3: Orientation 3.Orientation of sublevel  s = 1 orientation  p = 3 orientations  d = 5 orientations  f = 7 orientations

8. QN4: Electron Spin 4.Electron Spin “m s ”  s =  p =  d =  f = Hund’s Rule: Electrons occupy sublevels one at a time before filling up with a second electron. Pos. Spin= Neg. spin=

9. Electron Configurations (addresses) Electron Configuration: Tells us the location of an electron in the electron cloud. Pauli Exclusion Principle: No two electrons have the same configuration (address). Aufbau Principle: Electrons will occupy the lowest energy position (sublevel) available. (like tennis balls filling a tube)

10. Aufbau Principle: How orbitals are filled Complete the half-sheet and insert it into your ISN

11. Electron Configuration Examples Process 1.Determine the # of electrons 2.Fill up electrons in each energy sublevel Lowest  Highest 3.Don’t forget Hund’s Rule HW: Worksheet  write the first 20 element electron configurations due (Monday 11/16)