Periodic Table

Electron Configurations

• Aufbau Principle – electrons occupy the orbitals of lowest energy first

• Hund’s Rule - electrons fill orbitals in the same energy level first with electrons spinning the same direction and then the other direction

• Valence electrons are the ones in the highest occupied energy level.

• N, P, As, Bi have the same outer energy level configurations.

Order of Filling Diagram

1s

2s 2p

3s 3p 3d

4s 4p 4d 4f

5s 5p 5d 5f

6s 6p 6d 6f

7s 7p 7d

• The maximum number of electrons that can occupy one orbital is ____ • 2• Give the symbol and name of the elements that

correspond to these configurations of an atom.

• 1s 22s 22p 3 ____ ___________ • N Nitrogen• 1s 22s 22p 4 ____ ___________ • O Oxygen• 1s22s22p63s23p1 ____ ___________ • Al Aluminum

•

• 1s 22s 22p 63s 23p 2 ____ ___________

• Si Silicon• 1s 22s 22p 63s 1 ____ ___________ • Na Sodium• 1s 22s 22p 63s 23p 64s 1 ____

___________ • K Potassium• 1s 22s 22p 63s 23p 63d 24s 2 ____ ___________ • Ti Titanium

• How many valence electrons do the following elements have?

• oxygen ___________• 6• aluminum ___________• 3• sodium ___________• 1• barium ___________• 2

• The next atomic orbital in the series 1s, 2s, 2p, 3s, 3p is ____

• 4s• The electron configuration for fluorine is ________ • 1s22s22p5

• The correct electron configuration for • silicon, atomic number 14 is __________• 1s 22s 22p 63s 23p 2

• The configuration for the outermost (valence) energy level

• in Ca is _____ • 4s2

• Which orbital configuration is the valence electron configuration for each of these elements?

• sulfur _____• s2p4

• germanium _____• s2p2

• beryllium _____• s2

• krypton _____• s2p6

• strontium _____• s2

• Give electron configurations for atoms of these elements

• Na _________________ • 1s22s22p63s1

• S _________________ • 1s22s22p63s23p4

• Mg _________________ • 1s22s22p63s2

• Ne _________________ • 1s22s22p6

• K _________________ • 1s22s22p63s23p64s1

• selenium _________________ • 1s22s22p63s23p63d104s24p4

• vanadium _________________ • 1s22s22p63s23p63d34s1

• nickel _________________ • 1s22s22p63s23p63d84s2 • calcium _________________ • 1s22s22p63s23p64s2