1. Modern Atomic Model Crash Course: History of Atomic Theory (9:45) https://www.youtube.com/watch?v=thnDxFdkzZs Sometimes called: Sometimes called: Charge Cloud Model Charge Cloud Model Wave Mechanical Model Wave Mechanical Model Orbital Model Orbital Model Quantum Theory Quantum Theory

2. How is it Different from the Planetary Model? We can’t tell exactly where an electron is!! We can’t tell exactly where an electron is!! Heisenberg’s Uncertainty Principle: We can’t know exact location and momentum of an electron at the same time.

3. Electrons exist in “orbital clouds” Electrons exist in “orbital clouds” Denser the cloud region the higher the probability of finding an electron there. Denser the cloud region the higher the probability of finding an electron there. Can’t tell exactly where an electron is, but can tell region of higher probability of finding it. Can’t tell exactly where an electron is, but can tell region of higher probability of finding it.

4. Extra Videos Quantum Mechanics and the Bohr Model (6 minutes) Quantum Mechanics and the Bohr Model (6 minutes) Quantum Mechanics and the Bohr Model (6 minutes) Quantum Mechanics and the Bohr Model (6 minutes) http://www.youtube.com/watch?v=-YYBCNQnYNM http://www.youtube.com/watch?v=-YYBCNQnYNM http://www.youtube.com/watch?v=-YYBCNQnYNM Developing Modern Atomic Theory (6min) Rutherford to Bohr to the Modern Model http://youtu.be/45KGS1Ro-sc The Uncertainty Principle (6min) Honors Probability & Chance of Finding an e- and Orbital Shapes http://www.youtube.com/watch?v=Fw6dI7cguCg

5. How are Electrons Organized? Energy Levels SublevelsOrbitalsSpin The Electron Hotel

6. Energy Levels (1-7) Electrons exist at different distances from the nucleus. Electrons exist at different distances from the nucleus. Energy Levels Energy Levels 1 23 4 5 6 7 Lowest energyHighest energy Closest to nucleusFarthest from Nucleus

7. Sublevels (s, p, d, f) Energy levels have certain number of sublevels. Energy levels have certain number of sublevels. Energy LevelSublevels Possible 1s 2s, p 3s, p, d 4s, p, d, f 5s, p, d, f, (g) 6s, p, d, f, (g, h) 7s, p, d, f, (g, h, i) Theoretical sublevels

8. Energy of Sublevels Sublevels have different levels of energy. Sublevels have different levels of energy. spdf Lowest energyHighest energy

9. Orbitals in Sublevels Sublevels contain different numbers of orbitals. Sublevels contain different numbers of orbitals. Maximum 2 electrons can exist in an orbital. Maximum 2 electrons can exist in an orbital. Sublevel# of OrbitalsMax e - in Sublevel s12 e - s12 e - p36 e - d510 e - f714 e -

10. Aufbau Diagram Shows: Shows: order of electron filling order of electron filling order of electron energy order of electron energy Follow the “diagonal rule” Follow the “diagonal rule”

11. Writing Electron Configurations Let’s write some electron configurations! Let’s write some electron configurations! Ex: Magnesium Ex: Magnesium Follow the diagonal rule Follow the diagonal rule

12. Overlap Some sublevels “overlap” Some sublevels “overlap” Results in certain sublevels having higher energy than others Results in certain sublevels having higher energy than others Ex: 3d has higher energy than 4s Ex: 3d has higher energy than 4s

13. Electron Configurations for Atoms Electron Configurations for Atoms Electron Configurations for Atoms Electron Configurations for Atoms http://employees.oneonta.edu/viningwj/sims/atomic_electron_configurations_s1.html http://employees.oneonta.edu/viningwj/sims/atomic_electron_configurations_s1.html http://employees.oneonta.edu/viningwj/sims/atomic_electron_configurations_s1.html Extremely Corny Song About Electron Configurations Extremely Corny Song About Electron Configurations http://www.youtube.com/watch?v=Vb6kAxwSWgU&safe=active http://www.youtube.com/watch?v=Vb6kAxwSWgU&safe=active http://www.youtube.com/watch?v=Vb6kAxwSWgU&safe=active

14. Electron Spin Electrons in an orbital spin in opposite directions Electrons in an orbital spin in opposite directions Pauli Exclusion Principle: Pauli Exclusion Principle: In order for two electrons to occupy the same orbital, they must have opposite spins. Otherwise they create a magnetic field!

15. Orbital Diagrams Show electrons in individual orbitals Show electrons in individual orbitals s = 1 orbital, p = 3 orbitals, d = 5 orbitals, f = 7 orbitals s = 1 orbital, p = 3 orbitals, d = 5 orbitals, f = 7 orbitals “Hund’s Rule for Orbital Filling” “Hund’s Rule for Orbital Filling” When filling orbitals in a sublevel, place one electron in each orbital before adding the second. When filling orbitals in a sublevel, place one electron in each orbital before adding the second.

17. Paramagnetic vs. Diamagnetic Diamagnetic: only paired electrons in orbitals Paramagnetic: at least one orbital with an unpaired electron. Diamagnetic atoms repel magnetic fields. The unpaired electrons of paramagnetic atoms realign in response to external magnetic fields and are therefore attracted. Paramagnets do not retain magnetization in the absence of a magnetic field, because thermal motion randomizes the spin orientations.paramagnetic http://employees.oneonta.edu/viningwj/sims/electron_configurati ons_t2.html http://employees.oneonta.edu/viningwj/sims/electron_configurati ons_t2.html http://employees.oneonta.edu/viningwj/sims/electron_configurati ons_t2.html http://employees.oneonta.edu/viningwj/sims/electron_configurati ons_t2.html

18. Shapes of Orbitals Orbitals come in different shapes and sizes. Orbitals come in different shapes and sizes. Region of highest probability of finding an electron. Region of highest probability of finding an electron. Orbitals Shape & Energy & Spectral Line Orbitals Shape & Energy & Spectral Line http://www.youtube.com/watch?v=fKYso97eJs4 http://www.youtube.com/watch?v=fKYso97eJs4 http://www.youtube.com/watch?v=fKYso97eJs4

19. s Orbital Probability cloud has a spherical shape

20. p Orbitals (p x, p y, p z ) “Dumbell” shape Three p orbitals can exist, on the x, y, z axis in space

21. Clouds and Probability

22. d Orbitals Five possible d orbitals exist Five possible d orbitals exist

23. f Orbitals Seven possible f orbitals exist Seven possible f orbitals exist

24. Valence Electrons Usually found in the s and p sublevels of highest occupied energy level. Usually found in the s and p sublevels of highest occupied energy level. How many valence electrons? How many valence electrons? Draw a Lewis Dot Diagram of this element. Draw a Lewis Dot Diagram of this element. 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 2 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 2

25. Kernel All electrons except the valence All electrons except the valence How many kernel electrons? How many kernel electrons? How many valence? How many valence? 1s 2 2s 2 2p 6 3s 2 3p 3 1s 2 2s 2 2p 6 3s 2 3p 3

26. Excited vs. Ground State Ground State: Ground State: Electron configuration you would normally write by following the order of filling Electron configuration you would normally write by following the order of filling Lowest to highest energy. Lowest to highest energy. Excited State: Excited State: one or more electrons have jumped up to a higher energy level. one or more electrons have jumped up to a higher energy level. Ex: 1s 2 2s 2 2p 6 3s 2 3p 5 4s 2 3d 10 4p 3

27. Atom vs. Ion Configurations Ions: atoms that have gained or lost electrons. Ions: atoms that have gained or lost electrons. Figure out how many electrons the ion has then write configuration. Figure out how many electrons the ion has then write configuration. Ex: 20 Ca +2 has 18 electrons Ex: 20 Ca +2 has 18 electrons 1s 2 2s 2 2p 6 3s 2 3p 6 = 18 electrons DONE! 1s 2 2s 2 2p 6 3s 2 3p 6 = 18 electrons DONE! Electron Configurations for Ions http://employees.oneonta.edu/viningwj/sims/atomic_electron_configurations_s2.html

28. Impossible Configurations Break the rules. Break the rules. Ex: 1s 2 2s 2 2p 6 3s 2 2d 10 3p 6 4s 2 3d 10 4p 2 Ex: 1s 2 2s 3 2p 6 3s 2 3p 6

29. s, p, d, f, “Blocks” Indicates what sublevel is being filled last in the atom Indicates what sublevel is being filled last in the atom

30. Some Exceptions to Orbital Filling (HONORS) When d and f sublevels get filled near the end of a configuration we sometimes see exceptions. When d and f sublevels get filled near the end of a configuration we sometimes see exceptions. It is more stable for the orbitals of the d and f sublevels to be half filled or filled completely than to be one shy. It is more stable for the orbitals of the d and f sublevels to be half filled or filled completely than to be one shy. Electrons from the sublevel below get “promoted” up to make the atom more stable Electrons from the sublevel below get “promoted” up to make the atom more stable Ex: Copper Ex: Copper

31. Crash Course Chemistry: The Electron (13 minutes) http://www.youtube.com/watch?v=rcKilE9 CdaA http://www.youtube.com/watch?v=rcKilE9 CdaA http://www.youtube.com/watch?v=rcKilE9 CdaA http://www.youtube.com/watch?v=rcKilE9 CdaA

32. Quantum Numbers (Honors) Set of 4 numbers that help to describe most probable location of each of an atom’s electrons. Principal Quantum Number: (n) describes principle energy level electron is in values n = 1, 2, 3,...7 n=2 can describe the 8 electrons in 2 nd energy level

33. Azimuthal Quantum Number: (ℓ) Describes sublevel electron is in (s, p, d, f) Values of (ℓ) range from: 0 to (n-1) Ex: If n=4ℓ can be 0, 1, 2, 3 (representing s, p, d, f sublevels) If n=2 ℓ can be 0, 1 (representing s, p sublevels) n = 2 ℓ = 1means the electrons in 2”p” n = 3 ℓ = 2 means the electrons in 3 “d”

34. Magnetic Quantum Number: (m ℓ ) Describes the orbital the electron is in on sublevel Relates to it’s general orientation in space Values from (-ℓ….0….+ℓ) **note the middle orbital is ZERO Number of possible m values within a sublevel is = to the number of orbitals within a sublevel Ex: ℓ= 1 (p sublevel), m ℓ = -1, 0, +1 (representing p x, p y, p z orbitals) Ex:n= 3, ℓ= 2, m ℓ = -1 (describes the 2 electrons in the 2 nd orbital in 3d)

35. Spin Quantum Number: (m s ) Values of +1/2 or -1/2 (arrow up or arrow down) 1 st electron in orbital is “clockwise” = +1/2 2 nd electron in orbital is “counterclockwise” = -1/2 Ex: n=2, ℓ = 1, Ex: n=2, ℓ = 1, m ℓ = +1, m s = -1/2 Represents 2p 6 electron