STRUCTURE:Bonding S.C. BAYNE, 1 J.Y. Thompson 2 1 University of Michigan School of Dentistry, Ann Arbor, MI Nova Southeastern College of Dental Medicine, Ft. Lauderdale, FL

INTRODUCTION Quick review of elements and bonding. 1s 2s 2p 3s SODIUMAN=11 Atomic Weight = 22.99

PRIMARY BONDING Types. IONIC BONDINGCOVALENT BONDINGMETALLIC BONDING

PRIMARY BONDING Formation of bonds.

BONDING CHARACTER Mixed bonding character is the rule rather than the exception.

Theory of Electronegativity Distinguishing the degree of ionic-covalent bonding character. LiBeBCNOF NaMgAlSiPSCl KCaScTiVCrMnFeCoNaCuZnGaGeAsSeBr RbSrYZrNbMoTcRuThPdAgCdInSnSbTeI CsBa La/Lu HfTaWReOsIrPtAuHgTlPbBiPoAt FrRaAcThPaUNp/No TABLE OF ELECTRONEGATIVITIES

BAND STRUCTURE Energy band types and properties. 1s 2s 2p 3s SODIUM ATOM ENERGY  EMPTY 3s STATES FILLED 3s STATES FILLED 2d STATES FILLED 2s STATES FILLED 1s STATES Valence Band BAND THEORY ATOMIC SPACING 1s 2s 2p 3s FAR CLOSE ENERGY 

BAND STRUCTURE Energy band types and properties. Conduction Band Valence Band ENERGY GAP CONDUCTORSEMI-CONDUCTORINSULATOR

SECONDARY BONDING Hydrogen bonding, London disperson forces, and chelation. O C O CH 2 B. O H H O H H A. OCC H H H H OCC H H H H

CHELATION BONDING Hydrogen bonding, London disperson forces, and chelation.

QUICK REVIEW Review of bonding types. Which type of ELEMENT composes most of the periodic table? METAL Which PRIMARY BONDING type is involved with polymer? COVALENT What BONDING CHARACTER is associated with NiTi? IONIC, COVALENT, but MOSTLY METALLIC. How do you characterize a SEMI-CONDUCTOR using band theory? VALENCE BAND IS FULL, BUT SMALL ENERGY GAP. What SECONDARY BONDING type includes ionic and covalent bonding? CHELATION

THANK YOU