Energy Levels & Orbitals

1. Energy Levels & Orbitals

2. The Hydrogen Orbitals • Orbitals do not have sharp boundaries.

3. The Hydrogen Orbitals • Hydrogen has discrete energy levels. • Called principal energy levels • Labeled with whole numbers photon - An elementary particle, the quantum of the electromagnetic interaction and the basic unit of light. In other words a photon is a little packet of energy which can carry light.

4. The Hydrogen Orbitals • Each principal energy level is divided into sublevels. • Labeled with numbers and letters • Indicate the shape of the orbital

5. The Hydrogen Orbitals • The s and p types of sublevel

6. The Hydrogen Orbitals • Why does an H atom have so many orbitals and only 1 electron? • An orbital is a potential space for an electron. • Atoms can have many potential orbitals. • Hydrogen Orbitals

7. The Wave Mechanical Model: Further Development • The Bohr model was discarded because it does not apply to all atoms. • Atoms Beyond Hydrogen

8. The Wave Mechanical Model: Further Development • Pauli Exclusion Principle - an atomic orbital can hold a maximum of 2 electrons and those 2 electrons must have opposite spins

9. General Rules • Pauli Exclusion Principle • Each orbital can hold TWO electrons with opposite spins.

10. General Rules • Hund’s Rule • Within a sublevel, place one e- per orbital before pairing them. • “Empty Bus Seat Rule” RIGHT WRONG

11. General Rules • Aufbau Principle • Electrons fill the lowest energy orbitals first. • “Lazy Tenant Rule”

12. Sublevel s----------- p----------- d----------- f----------- Orbitals 1 3 5 7

13. Electron Arrangements in the First 18 Atoms on the Periodic Table • Valence electrons – electrons in the outermost (highest) principal energy level of an atom • Core electrons – inner electrons • Elements with the same valence electron arrangement show very similar chemical behavior. • Classifying Electrons

14. 2s 2p 1s Notation • Orbital Notation O 8e- • Electron Configuration 1s22s22p4

16. Core Electrons Valence Electrons Notation • Longhand Configuration S 16e- 2p6 2s2 1s2 3s2 3p4 • Shorthand Configuration S 16e-[Ne]3s2 3p4

17. Electron Configurations and the Periodic Table • Orbital filling and the periodic table

18. 1 2 3 4 5 6 7 s p d (n-1) 6 7 f (n-2)

20. p s d (n-1) f (n-2) Periodic Patterns • Shorthand Configuration • Core e-: Go up one row and over to the Noble Gas. • Valence e-: On the next row, fill in the # of e- in each sublevel.

21. Periodic Patterns • Example - Germanium 4s2 3d10 4p2 [Ar]

22. H atom • Electron configuration – electron arrangement – 1s1 • Orbital diagram – orbital is a box grouped by sublevel containing arrow(s) to represent electrons

23. He atom • Electron configuration– 1s2 • Orbital diagram

24. Li atom • Electron configuration– 1s2 2s1 • Orbital diagram

25. Energy Level Diagram 6s 6p 5d 4f Bohr Model 5s 5p 4d 4s 4p 3d Arbitrary Energy Scale 3s 3p 2s 2p 1s Electron Configuration NUCLEUS H He Li C N O F CLICK ON ELEMENT TO FILL IN CHARTS

26. Energy Level Diagram Hydrogen 6s 6p 5d 4f Bohr Model 5s 5p 4d 4s 4p 3d Arbitrary Energy Scale 3s 3p N 2s 2p 1s Electron Configuration H = 1s1 NUCLEUS H He Li C N Al Ar F Fe La CLICK ON ELEMENT TO FILL IN CHARTS

27. Energy Level Diagram Helium 6s 6p 5d 4f Bohr Model 5s 5p 4d 4s 4p 3d Arbitrary Energy Scale 3s 3p N 2s 2p 1s Electron Configuration He = 1s2 NUCLEUS H He Li C N Al Ar F Fe La CLICK ON ELEMENT TO FILL IN CHARTS

28. Energy Level Diagram Lithium 6s 6p 5d 4f Bohr Model 5s 5p 4d 4s 4p 3d Arbitrary Energy Scale 3s 3p N 2s 2p 1s Electron Configuration Li = 1s22s1 NUCLEUS H He Li C N Al Ar F Fe La CLICK ON ELEMENT TO FILL IN CHARTS

29. Energy Level Diagram Carbon 6s 6p 5d 4f Bohr Model 5s 5p 4d 4s 4p 3d Arbitrary Energy Scale 3s 3p N 2s 2p 1s Electron Configuration C = 1s22s22p2 NUCLEUS H He Li C N Al Ar F Fe La CLICK ON ELEMENT TO FILL IN CHARTS

30. Energy Level Diagram Nitrogen 6s 6p 5d 4f Bohr Model 5s 5p 4d 4s 4p 3d Arbitrary Energy Scale 3s 3p N Hund’s Rule “maximum number of unpaired orbitals”. 2s 2p Electron Configuration 1s N = 1s22s22p3 NUCLEUS H He Li C N Al Ar F Fe La CLICK ON ELEMENT TO FILL IN CHARTS

31. Energy Level Diagram Fluorine 6s 6p 5d 4f Bohr Model 5s 5p 4d 4s 4p 3d Arbitrary Energy Scale 3s 3p N 2s 2p Electron Configuration 1s F = 1s22s22p5 NUCLEUS H He Li C NAl Ar F Fe La CLICK ON ELEMENT TO FILL IN CHARTS

32. Energy Level Diagram Aluminum 6s 6p 5d 4f Bohr Model 5s 5p 4d 4s 4p 3d Arbitrary Energy Scale 3s 3p N 2s 2p Electron Configuration 1s Al = 1s22s22p63s23p1 NUCLEUS H He Li C NAl Ar F Fe La CLICK ON ELEMENT TO FILL IN CHARTS

33. Energy Level Diagram Argon 6s 6p 5d 4f Bohr Model 5s 5p 4d 4s 4p 3d Arbitrary Energy Scale 3s 3p N 2s 2p 1s Electron Configuration Ar = 1s22s22p63s23p6 NUCLEUS H He Li C N Al Ar F Fe La CLICK ON ELEMENT TO FILL IN CHARTS

34. Energy Level Diagram Iron 6s 6p 5d 4f Bohr Model 5s 5p 4d 4s 4p 3d Arbitrary Energy Scale 3s 3p N 2s 2p 1s Electron Configuration Fe = 1s22s22p63s23p64s23d6 NUCLEUS H He Li C N Al Ar F Fe La CLICK ON ELEMENT TO FILL IN CHARTS

35. Energy Level Diagram Lanthanum 6s 6p 5d 4f Bohr Model 5s 5p 4d 4s 4p 3d N Arbitrary Energy Scale 3s 3p 2s 2p 1s Electron Configuration La = 1s22s22p63s23p64s23d6 4s23d104p65s24d105p66s25d1 NUCLEUS H He Li C N Al O F Fe La CLICK ON ELEMENT TO FILL IN CHARTS

36. B. Electron Configurations and the Periodic Table • Look at electron configurations for K through Kr

37. Electron Configurations and the Periodic Table

38. C. Periodic Patterns • Period # • energy level (subtract for d & f) • A/B Group # • total # of valence e- • Column within sublevel block • # of e- in sublevel

39. Atomic Properties and the Periodic Table Metals and Nonmetals • Metals tend to lose electrons to form positive ions. • Nonmetals tend to gain electrons to form negative ions.

40. Atomic Properties and the Periodic Table Atomic Size • Size tends to increase down a column. • Size tends to decrease across a row.

41. Atomic Properties and the Periodic Table Ionization Energies • Ionization Energy – energy required to remove an electron from an individual atom (gas) • Tends to decrease down a column • Tends to increase across a row