Understanding Electron Configuration and Periodic Table Concepts

1. 19 October 2009 Chapter 5-7 Notes Mr. Herbst Room 2705

2. Important terminology/concepts: • Orbital – three dimensional region around the nucleus that indicated the probable location of an atom • Pauli exclusion principle – no two electrons can be in the same place at the same time • Hund’s rule – electrons prefer to be unpaired and unpaired electrons in the same orbital spin in the opposite direction • Electron configuration – the arrangement of electrons in an atom

3. Predicting Electron Location • Necessary b/c chemical properties are determined by electrons (though we can only predict probable location; they are always moving • Ground State - the lowest allowable energy state of an atom (not an excited state)

4. Shell Theory & Energy levels

5. Sublevels and Orbitals • In each level of electrons, there are 4 sublevels • ‘s’; 1 orbital; 2 electrons • ‘p’; 3 orbitals; 6 electrons • ‘d’; 5 orbitals; 10 electrons • ‘f’; 7 orbitals; 14 electrons

6. Orbital Notation • One way to show electron ‘position’ • draw boxes for the sublevels; write one arrow for each electron • arrows in the same box need to be opposite • arrows need to be unpaired when possible

7. LEAVE SPACE HERE!!!! • About 1 page

8. 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 7s 7p

9. Sublevels on the periodic table

10. Electron configuration DIAGRAM

11. Electron configuration NOTATION • electron configuration notation for nitrogen: 1s22s22p3 • electron configuration notation for oxygen: 1s22s22p4

12. Chapter 6 Notes • The Periodic TableTrends, Properties of the elements

15. Periodic Law - The properties of the elements repeat periodically when the elements are arranged by atomic number - Dmitri Mendeleev - father of the modern periodic table • Series - Horizontal row on the periodic table (also called row or level) • Family - Vertical column on the periodic table (also called group or column)

16. Families of the periodic table • Alkali Metals = Group IA- so called because they form alkali (basic)solutions with water (does not include Hydrogen) • Alkaline Earth Metals = Group IIA- also form basic solutions • Halogen family = Group VIIA “Salt formers”

17. Noble Gases = Group VIIIA also called INERT GASES • - all have full s and p orbitals (called a stable octet) • - are unreactive- all other elements want this same orbital configuration

18. ALL OTHER FAMILIES ARE NAMED FOR THE FIRST ELEMENT IN THE COLUMN • Representative elements = Groups IA - VIIA • Transition Metals = Group B - located in the center of the table (may form one or more ion) • Inner Transition Metals = removed from the table (Actinides & Lanthanides)

19. Metals - on the left side of the table 1. Want to lose electrons- form _____ ions 2. Are malleable and ductile 3. Conduct heat and electricity 4. From strong ionic compounds with non-metals 5. Low electronegativity and ionization energy • Metallic character increases to the left and down on the table

20. Non-Metals - On right side of the table 1. Want to gain electrons- form ______ ions 2. Form strong ionic compounds with metals (not noble gases) 3. High electronegativity and ionization energy • Non-Metallic character increases to the right and up on the table

21. Metalloids - exhibit properties of both metals and non-metals • Lie along the stairstep line on the periodic table • Electronegativity- measure of attraction an atom has for electrons • Ionization energy- amount of energy needed to remove an electron from an atom

22. Electron Dot Structures • Valence electrons are the furthest away from the nucleus and are involved in chemical reactions • Valence number can be predicted from the periodic table (Same as Column #) • Electron dot structures are a simple way to show the number of valence electrons