1. Electron Configuration

2. Evaluation/ Assessment
Objective
Today I will be able to:
Calculate the electron configuration for elements on the periodic table
Evaluation/ Assessment
Informal assessment – student responses when reviewing electron configuration problems. Listening to group interactions on practice sheets
Formal Assessment – collecting and analyzing responses to electron configuration worksheet 2

3. Lesson Sequence Warm – Up
Explain: How to write electron configurations
Elaborate: write electron configurations with a partner for questions 1-18
Evaluate: review the questions as a class (informal assessment)
Explain: electron configurations in 3d orbitals and Aufbau diagrams
Elaborate: Students will complete on electron configuration WS with a partner
Evaluate: review the questions as a class (informal assessment)
Explain: abbreviated electron configurations
Elaborate: Students will add a column to the WS and repeat write the abbreviated configuration
Evaluate: Abbreviated configurations will be reviewed as a class (informal assessment)
Exit Ticket

4. Warm - Up
According to the modern atomic theory (Schrodinger’s model) where are the electrons located?
According to the Bohr model, where are the electrons located?

5. Objective Today I will be able to:
Calculate the electron configuration for elements on the periodic table

6. Homework
Have a great afternoon! 

7. Agenda Warm – Up Electron Configuration Notes
Electron Configuration Practice
Exit Ticket

8. Electron Configuration

9. Label and color your periodic table to match the periodic table on the next slide…

10. Electron Configuration1 2 3 4 5 6 7
p-block
s-block
d-block
n-1
f-block
n-2

11. Electron Configuration
“address” of where each individual electron is located in an atom
1s2
Number of electrons
in the orbital
Energy Level (n)
Orbital

12. (Principal) Energy Level
Symbol = n
As atoms get bigger, there are more electrons, therefore more energy levels
Fill the lowest energy levels first (ground state)
Within each energy level, we have one or more sublevels
These sublevels are called orbitals

13. Orbitals Based on modern model of atom
3-D region around the nucleus indicating the probable location of the electron
4 types of orbital (low  high energy) s p d f

14. Orbital Shapes

15. Orbitals cont. Each sublevel can hold a specific amount of electrons

16. Now we can put these ideas together and write an electron configuration for an atom…

17. Examples Sodium (Na) Cobalt (Co) Has 11 electrons (when neutral)
Electron Configuration:
1s22s22p63s1
Cobalt (Co)
Has 27 electrons (when neutral)
Electron Configuration
1s22s22p63s23p64s23d7

18. Electron Configuration Practice
Complete numbers 1-18

19. Why does 4s come before 3d?
3d is of slightly higher energy than 4s, but 4s is further from the nucleus
It takes less energy for a 3d electron to form pairs then a 4s electron

20. Aufbau Diagram
Instead of using the periodic table as a road map, you can use the aufbau diagram to determine the order that the electrons occupy the different energy levels
Electrons fill the lowest energy orbitals first

21. Aufbau Diagram

22. Complete Electron Configuration Practice Worksheet 19 - 36

23. Abreviated Electron Configuration
Scientists are lazy 
We need a shorthand way to represent electron configuration
How do we do this?
Noble Gas Configuration

24. Noble Gas Configuration
The last column on the periodic table is referred to as the noble gases
To write in abbreviated configuration:
Find the last noble gas within the configuration
Write the symbol
Write the remaining configuration
Example
Ca - 1s2 2s2 2p6 3s2 3p6 4s2
Noble Gas Configuration = [Ar] 4s2

25. Noble Gas Configuration
Writing Noble Gas Configurations for ions is a little bit different
Must account for an electron being gained or lost
Chlorine Ion = Cl-1
[Ne] 3s2 3p6
Sodium Ion = Na+1
[He] 2s2 2p6

26. Electron Configuration Practice
Go back and write the Abbreviated (Noble Gas) configuration for the elements on the worksheet on the right hand margin

27. Visualizing Orbital's of Electrons

28. z y
The 3 axes represent
3-dimensional space x

29. z y
The nucleus of the atom is at the center of the three axes x

30. The 1s orbital is a
sphere, centered
around the nucleus

31. The 2s orbital is also
a sphere

32. The 2s electrons have a
higher energy than the 1s
electrons. Therefore, the 2s
electrons are generally more
distant from the nucleus,
making the 2s orbital larger
than the 1s orbital

33. There are three
2p orbitals

34. The three 2p orbitals
are oriented
perpendicular
to each other

35. z
This is
one 2p orbital
(2py) y x

36. z
Another 2p orbital
(2px) y x

37. z
The third 2p orbital
(2pz) y x

38. z
2px y x

39. z
2px and 2pz y x

40. z
The three 2p orbitals,
2px, 2py, 2pz y x

41. Once the
1s orbital
is filled…

42. The 2s orbital
begins to fill

43. Once the 2s
orbital is
filled…

44. The 2p orbitals
begin to fill

45. Each 2p orbital
intersects the
2s orbital and
the 1s orbital

46. Each 2p orbital
gets one electron
before pairing begins

47. Once each 2p orbital
is filled with a pair
of electrons, then…

48. The 3s orbital
gets the next
two electrons

49. The 3s electrons
have a higher energy
than 1s, 2s, or 2p
electrons

50. 3s electrons are
generally found
further from the
nucleus than 1s,
2s, or 2p electrons

51. Exit Ticket Mol Monday # 1
How many molecules of CO are in 5.0 grams of CO?

52. Exit Ticket
Write the electron configuration of sulfur