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 8 3s and 3p n = s, 3d and 4p n = s, 4d and 5p

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

Sublevels continued The maximum number of electrons allowed in each sublevel are as follows: s = max 2 electrons s = max 2 electrons p = max 6 electrons p = max 6 electrons d = max 10 electrons d = max 10 electrons f = max 14 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 four 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 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 on your sheet to depict the location of the different orbitals.

1s1s 2s2p 3s3p 4s3d4p 5s4d5p 6s5d6p 7s6d7p 4f 5f

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 types 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.

The End!

1s1s 2s2p 3s3p 4s3d4p 5s4d5p

1s11s2 2s12s22p12p22p32p42p52p6 3s13s23p13p23p33p43p53p6 4s14s23d13d23d33d43d53d63d73d83d9 3d 10 4p14p24p34p44p54p6 5s15s24d14d24d34d44d54d64d74d84d9 4d 10 5p15p25p35p45p55p6 This is read from left to right, and top to bottom. Example: Carbon: 1s 2 2s 2 2p 2 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: Sodium [Ne] 1s1

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:____________________________________