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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.
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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 completelyfilled level is considered very stable. • The number of electrons allowed in each level is indicated below:
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 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!
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.
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)
Young Friederich Hund Wolfgang Pauli I threw this in there because you know how much I love my old scientists! ;) OldFriederich Hund
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
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 ConfigurationsRemember 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:____________________________________