Unit 4 Topic 1 SPDF

Principal Energy Levels Electrons occupy principal energy levels around the nucleus of the atom These energy levels represent specific distances from the nucleus. Each energy level n = 1 to n = 7, is farther from the nucleus

Principal Energy Levels Cont Each Principal Energy Level (n) has a specific number of electrons which are allowed to occupy that level. A completely filled level is considered very stable. The number of electrons allowed in each level is indicated below:

Principal E Level Max # Electrons Sublevel type n = 1 2 1s only n = 2 8 2s and 2p n = 3 3s and 3p n = 4 18 4s, 3d and 4p n = 5 5s, 4d and 5p

Sublevels Each principal energy level is divided up into sublevels (s, p, d & f) The s and p sublevel electrons in the outermost energy level of an atom represent the valence electrons for a given element. The same group (column) of the periodic table have the same number of valence electrons

This is just a picture of the orbitals. Aren’t these crazy looking This is just a picture of the orbitals. Aren’t these crazy looking? This is why we just draw Bohr models even though we know they are not correct.

Sublevels continued The maximum number of electrons allowed in each sublevel are as follows: s = max 2 electrons p = max 6 electrons d = max 10 electrons f = max 14 electrons

Structure of Periodic Table The structure of the periodic table can be related to the electronic structure of the atom Each row (period) corresponds to the principal energy levels in an atom So if an element occupies the fourth row, then it has electrons occupying the first 3 energy levels being filled with the maximum number of electrons allowed for that level

Column (Group) Each Column (group) corresponds to the sublevel being occupied by the atoms electrons: Group 1 fills the first s orbital Group 2 fills the second s orbital Groups 3-12 fill the first d orbital through the tenth d orbital Groups 13-18 fill the first p orbital through the sixth d orbital (except for He)

Coloring the Orbitals Create a Color/Pattern code and fill in the periodic table in your coloring book to depict the location of the different orbitals. Label the Table and remember a CODE!

Electron Configurations 2 s p 3 4 d 5 6 7 f Electron Configurations

Valence Electrons The electronic structure of the atom (and the periodic table) are used to determine the number of valence electrons in the atom of an element. The valence electrons are the s and p orbitals in the outermost energy level occupied by electrons. This allows you to keep track of them by the columns of the periodic table.

Fill out.. Fill out the Data table on your worksheet The first one has been completed for you as an example. Remember when you are doing the dot diagrams to place a dot on all four sides FIRST before pairing.

1 ns1 +1 2 ns2 +2 13 ns2 np1 +3 14 ns2 np2 + or – 4 15 ns2 np3 -3 16 Group # Electron Config # Valence Dot Diagram Oxidation # 1 ns1 +1 2 ns2 +2 13 ns2 np1 +3 14 ns2 np2 + or – 4 15 ns2 np3 -3 16 ns2 np4 -2 17 ns2 np5 -1 18 ns2 np6

Definitions Add these definitions into your vocab Pauli Exclusion Principle – No more than two electrons can occupy a single orbital Aufbau Principle – German word for “building up”. Electrons fill orbitals with lowest energy first. Hund’s Rule – Orbitals must each occupy one electron before pairing. (Bus Rule)

Wolfgang Pauli Young Friederich Hund Old Friederich Hund I threw this in there because you know how much I love my old scientists! ;) Old Friederich Hund

The End!

1s 2 s p 3 4 d 5 6 7 f

1s 2 s p 3 4 d 5 6 7 f Noble Gas Method : Put the noble gas representing the last filled energy principal level in brackets [ ] and then list the rest of the electronic configuration Example: Potassium (K) = [Ar] 4s1

1s 2 s p 3 4 d 5

This is read from left to right, and top to bottom. Example: Carbon: 1s2 2s2 2p2 Noble Gas Method : Put the noble gas representing the last filled energy principal level in brackets [ ] and then list the rest of the electronic configuration Example: Potassium (K) = [Ar] 4s1

Electronic Configurations Remember to use the SUPERSCRIPTS Write out the electronic configurations for the following Elements: Nitrogen :______________________________________ Helium:________________________________________ Lithium:________________________________________ Sulfur: ________________________________________ Chromium:_____________________________________ Write out the electronic configurations using the Nobel Gases Method Zinc:__________________________________________ Rubidium:______________________________________ Chlorine:_______________________________________ Silver:_________________________________________ Magnesium:____________________________________