FACT:

1. FACT: Chemical reactions happen because electrons are shared or transferred from one substance to another

2. MAX NUMBER OF ELECTRONS IN AN ENERGY LEVEL

3. Write a mathematical equation that allows us to predict the Max # if we knowthe energy level (n) Max # = …n…

4. Equation to calculate Max # of e- 2n2 Where n is any energy level

5. Obviously something is wrong… because the electrons fill in an unexpected order. We need a more complicated system!

6. There are 4 Quantum #s and those #s are used to describe where an electron is likely to be found at any given time

7. This is a lot like being able to use four “places” to describe EXACTLY where Mrs. BB-G should be at 7:00AM on Friday.

8. The Principle Quantum # = n The first number we already know… (a.k.a. The Electron Energy level)

9. Specifies the electron energy level that the electron is on Principle Quantum # n = 1, 2, 3, 4, 5, 6, 7

10. Principle Quantum # (Floor number in our school building) 2nd Floor

11. ℓ = s, p, d, f 2nd Quantum # = ℓ Specifies the shape of the orbital or sub-energy level

12. Second Quantum # Students (sleeping) (s)sitting prone at desk (p)“darn” I have to sit up (d)forget this standing up in class (f) ℓ = s, p, d, f

13. p d f s

14. Sub-Energy Levels

15. 3rd Quantum # = m m = x,y,z 3-d World Like tables arranged at different angles in the classroom

16. Sub-Energy Levels s,p,d,f

17. 4th Quantum # = ms ms = + ½or–½ Clockwise or counterclockwise Specifies the electron’s spin

18. QUANTUM NUMBERS n ---> shell 1, 2, 3, 4, ... l ---> subshell s,p,d,f ml ---> orbital x,y,z ( 3-D) ms ---> electron spin

19. PERIODIC TABLE review

20. Periods and Groups

21. PERIODS • The number of each period shows the principal energy level

22. 1 2 3 4 5 6 7 Lanthanide 4f Actinide 5f

23. PERIODS • Horizontal rows of the table are called periods or rows.

24. GROUPS • The vertical columns of the Periodic Table are called groups or families.

25. Group Designations • The traditional designation for each group has been a combination of a Roman numeral and the letter A or B, such as IA or IIB. • These designations are often used along side of a new form which numbers the groups from 1 to 18.

26. lA 0 1 lllA lVA VA VIA VlIA llA 2 3 lllB lVB VB VlB VllB VlllB lB llB 4 5 6 7

27. Groups At F O N Home 18 1 Diatomic Elements H2 N2 O2F2Cl2Br2I2 2 13 14 15 16 17 Transition Metals 9 3 4 5 6 7 8 10 11 12

28. NON-METALS METALS METALLOIDS

30. DIAGONAL RULEOrder of Filling orbitals due to increasing energy (Lowest energy level – 1) • Draw a diagram putting each energy shell on a row . • Listing the orbitals, (s, p, d, f), (left-to-right) 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 7s 7p • Next, draw arrows through the diagonals, looping back to the next diagonal each time Aufbau Principle electrons will fill orbitals of lowest energy first, then fill according to increasing energy.

31. Diagonal Rule • Steps: • Write the energy levels top to bottom. • Write the orbitals in s, p, d, f order. Write the same number of orbitals as the energy level. • Draw diagonal lines from the top right to the bottom left. • To get the correct order, follow the arrows! 1 2 3 4 5 6 7 s s 2p s 3p 3d s 4p 4d 4f By this point, we are past the current periodic table so we can stop. s 5p 5d 5f 5g? s 6p 6d 6f 6g? 6h? s 7p 7d 7f 7g? 7h? 7i?

32. ORBITAL Space occupied by a pair of electrons

33. Four Sub-Energy Levels

34. So why do electrons fill in like they do? i.e. Why is K’s last electron in the 4th energy level?

35. 2 Factors Influencing Electron Placement • Energy Level • - Closer to nucleus=easy 2. Orbital or Subenergy level (shape) - spdf

36. Electron Configuration A detailed way of showing the order in which electrons fill in around the nucleus

37. # of e- in sub-energy level Electron Configuration Symbols 5f3 Sub-Energy Level Energy Level

38. Electron Configurations 2p4 Number of electrons in the sublevel Energy Level Sublevel 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14…etc.

39. Electron Configuration PT 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14…etc.

40. Writing Electron Configurations • Strategy: start with hydrogen, and build theconfiguration one electron at a time(Aufbau principle) • 1. In the H put 1s1; above He put 1s2; in Li 2s1, Be 2s2, In B put 2p1; in C put 2p1; etc across the chart. • 2. Fill subshells in order by counting across periods, from hydrogenup to the element of interest: Click here

41. PERIODIC TABLE WORKSHEET Give the location of the last electron for all of the elements on the periodic table below. 1s2 1s1 2s1 2p1 2p2 2s2 4s2 3d1 5d1 5d5 6p3 5f1 Click here…

43. Bohr Models vs. Electron Configurations K K: 1s2 3s2 3p6 4s1 2p6 2s2

44. 1s1 Write the e-config for: 1s2 He: Li: 1s22s1 H: K: 1s22s22p63s23p64s1 Al: 1s22s22p63s23p1

45. Keep an Eye On Those Ions! • Electrons are lost or gained like they always are with ions… • negative ions have gained electrons, positive ions have lost electrons • The electrons that are lost or gained should be added/removed from the highest energy level (not the highest orbital in energy!)

46. Keep an Eye On Those Ions! • Tin Atom: [Kr] 5s2 4d10 5p2 Sn+4 ion: [Kr] 4d10 Sn+2 ion: [Kr] 5s2 4d10 Note that the electrons came out of the highest energy level, not the highest energy orbital!

47. Keep an Eye On Those Ions! • Bromine Atom: [Ar] 4s2 3d10 4p5 Br- ion: [Ar] 4s2 3d10 4p6 Note that the electrons went into the highest energy level, not the highest energy orbital!

48. Again…Why are we concerned so much about electrons?

49. Valence Electrons Electrons in the outermost energy level (involved in chemical reactions)

50. Nobel Gas Configuration • Find the symbol for the element zinc. [Zn] 2. Write the symbol in brackets for the nearest, smaller noble gas. [Ar] 3. Write the outer electron configuration for the remaining electrons. [Ar] 4s2 3d10 1s22s22p63s23p4 Ex. 1.S [Ne]3s23p4 1s22s22p63s23p64s23d104p65s24d105p66s24f145d4 2. W [Xe]6s24f145d4