1. Flame Test, Electron Configuration

2. Warm - Up What is a photon?
How can we identify elements based on their emission spectrum?
What is the Photoelectric Effect?
Why do we say that light has a dual nature?

3. Objective Today I will be able to:
Analyze the emission of energy in metals by completing a flame test
Calculate the electron configuration for elements on the periodic table

4. Homework
Electron Configuration Practice

5. Agenda Warm – Up Flame Test Lab Electron Configuration Notes
Electron Configuration Practice
Exit Ticket

6. Electron Configuration

7. Electron Configuration
Electron configuration – arrangement of electrons in an atom
Electrons try to populate the lowest energy levels available – “ground state”

8. Arrangement of Energy Levels
Principal energy levels – represented by n
As atoms get bigger, there are more electrons, therefore more energy levels
Within each energy level, we have one or more sublevels
These sublevels are made up of orbitals

9. Energy Levels on the Periodic Table

10. Orbitals
According to modern atomic theory electrons are found in orbitals
Orbital – 3-D region around the nucleus indicating the probable location of the electron
There are 4 types of orbitals where the electrons can be found – s,p,d,f
Order of energy from lowest to highest:
s, p, d, f

11. 3-D images of the orbital's

12. Energy Sublevels
Each sublevel occupies a specific location on the periodic table:

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

14. Arrangement of Energy Levels
Sublevels 1 1s 2
2s, 2p 3
3s, 3p, 3d 4
4s, 4p, 4d, 4f 5
5s, 5p, 5d, 5f, 5g (rarely seen)

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

16. Electron Configurations
We can write the electron configurations for each element (assuming the atom has a neutral charge) representing the location of the elements electrons in the energy levels

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. Why does 4s come before 3d?
3d is of slightly higher energy than 4s, but 4s is further from the nucleus

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

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

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

22. The 2s orbital is also
a sphere

23. 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

24. There are three
2p orbitals

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

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

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

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

29. z
2px y x

30. z
2px and 2pz y x

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

32. Once the
1s orbital
is filled…

33. The 2s orbital
begins to fill

34. Once the 2s
orbital is
filled…

35. The 2p orbitals
begin to fill

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

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

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

39. The 3s orbital
gets the next
two electrons

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

41. 3s electrons are
generally found
further from the
nucleus than 1s,
2s, or 2p electrons

42. Exit Ticket
Explain the mechanism behind different colored fireworks