Chem 233 1st Edition Lecture 1 Outline of Last Lecture I. Introduction into Organic Chemistry and the TeacherOutline of Current Lecture II. Types of BondsIII. Hunds Rule DefinitionIV. Two PrinciplesV. S & P Orbitals VI. Length and Strength of BondsCurrent LectureTypes of Bonds-Ionic Bonds: Transfer of electrons to maintain octet (Example: Na + Cl -> NaCl) -Covalent Bonds: Sharing of electrons to maintain octet (Example: F + F -> F-F)Hunds Rule Definition-When degenerate orbitals are present, an electron will occupy and empty orbital before it will pair up with another electron. Core electrons are located in the inner shells and valence electrons are located in the outermost shell.Two Principles-Aufbau Principle: an electron always goes into the available orbital with the lowest energy -Pauli Exclusion Principle: no more than 2 electrons may occupy an orbital and must be opposite spinS & P Orbitals-sp=linear…180 degrees…one sigma bond and two pi bonds -sp^2=trigonal planar…120 degrees…one sigma bond and one pi bond -sp^3=tetrahedral…109.5 degrees…one sigma bondLength and Strength of Bonds-The longer the bond, the weaker it will be -When looking at the halides, the HI bond is the weakest and the HF bond is the strongest -The weaker the bond the stronger the acid -The bond strength order is single<double<triple -The pi bond is also weaker than the sigma