1. A TOMIC O RBITALS AND E LECTRON C ONFIGURATIONS

2. Waves  Electrons behave like waves.  The distance between corresponding points on adjacent waves is the wavelength ( ).  The number of waves passing a given point per unit of time is the frequency ( ).

3. Waves The number of waves passing a given point per unit of time is the frequency ( ).

4. The Nature of Energy Max Planck explained it by assuming that energy comes in packets called quanta. Quantum of energy is the amount of energy required to move an electron from one energy level to another energy level.

5. Moving to an Excited State Ground state Excited state Incoming Energy Outgoing Energy Ground state Excited state

6. Electron Energy The electrons with the lowest energy are located nearest the nucleus. Ground state electrons- electrons with their normal amount of energy for that energy level. Excited state electrons- electrons that have absorbed energy and moved to a higher energy level farther from the nucleus.

7. Atomic Emission Spectrum When atoms electrons lose energy they emit light Each atom has a specific light pattern it gives off known as atomic emission spectrum.

8. More colors were seen than could be explained by Bohr’s Model.

9. Quantum Mechanics Erwin Schrödinger developed a mathematical treatment into which both the wave and particle nature of matter could be incorporated. It is known as quantum mechanics.

10. Heisenberg Uncertainty Principle: you can never know the speed and location of an electron simultaneously.

11. E NERGY L EVELS Each row on the periodic table is a different principle energy level Row 1 would be level 1 Row 2 would be level 2 and so on. Energy levels can be broken down into sublevels, or different shaped orbital's.

12. A TOMIC O RBITALS A region of space in which there is a high probability of finding an electron 4 different types of sub-levels S P D F

13. Sub-level S Spherical Shape Sublevel s has 1 orbital Holds 2 electrons

14. Sub-Level P Dumbbell Shaped has 3 orbital's Holds 6 electrons

15. Sub Level D Clover Shaped has 5 orbital's Holds 10 electrons

16. Sub-Level F 7 orbital's Hold 14 electrons

17. O RBITAL D IAGRAMS Orbital's will be shown as boxes Electrons will be shown as arrows Each orbital (box) can hold two electrons (arrows)

18. Aufbau Principle- Electrons occupy the orbital's of lowest energy first. Fill from bottom to top. Fill each set of orbital's before moving to a higher orbital

19. Pauli Exclusion Principle- Two electrons in the same orbital must have opposite spins + N N N N S S S S - The magnetic field effects of paired electrons help keep them in the same orbital.

20. Hund’s Rule Electrons occupy orbital's of the same energy in a way that makes the number of electrons with the same spin direction as large as possible.

21. O RBITAL D IAGRAMS 1. Find the total number of electrons from the periodic table 2. Fill each orbital in the orbital filling diagram according to the three principals. 1. Fill from bottom to top 2. Two electrons in the same orbital must have opposite spins 3. Pair electrons in the same orbital only when there is no other option * Each orbital (box) can hold two electrons (arrows)

22. 1s 2s 2p 3s 3p 3d 4s 4p 5s Element: Lithium

23. 1s 2s 2p 3s 3p 3d 4s 4p 5s Element: Oxygen Atomic Number 8

24. 1s 2s 2p 3s 3p 3d 4s 4p 5s Element: Chlorine Atomic Number 17

25. 1s 2s 2p 3s 3p 3d 4s 4p 5s Element: Strontium Atomic Number 38

26. W RITING E LECTRON CONFIGURATIONS FROM O RBITAL DIAGRAMS Write the energy level and the symbol for every sublevel occupied by an electron. Indicate the number of electrons occupying that sublevel with a superscript. 1s 1 Write each orbital in the same order that you filled in using the orbital filling diagram 1s

27. Writing the Condensed method for electron configuration Condensed method is a short hand way to write electron configurations. Consists of electron configuration of the valence electrons and the symbol of the noble gas from the previous period in brackets.

28. Condensed Method 1s 2 2s 2 2p 6 3s 2 3p 3 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 6 [Ne] 3s 2 3p 3 [Ar] 4s 2 3d 6

29. Periodic Table We fill orbitals in increasing order of energy. Different blocks on the periodic table, then correspond to different types of orbitals.

30. Some Anomalies Some irregularities occur when there are enough electrons to half-fill s and d orbitals on a given row.

31. Some Anomalies For instance, the electron configuration for copper is [Ar] 4 s 1 3 d 5 rather than the expected [Ar] 4 s 2 3 d 4.