CHEM101 Lecture 10: 10 Crystalline solids_1_Postlecture

• School: University of Alberta
• Department: Chemistry
• Course: CHEM101
• Professor: Sai Yiu

Document Summary

Introductory university chemistry i (chem 101 / 103) Crystalline solid is a solid where the atoms, ions, or molecules are in order and well-defined arrangements. Amorphous solid is a solid whose particles have no orderly structure. There are five different types of crystalline solids: Very hard, very high melting point (graphite is soft) Separate particles form a giant crystalline structure by covalent bonds. They are connected by bonds to form a giant network. It is a non-conductor of electricity: high melting solid (m. p. = 3500o c) (melting involves breaking all the covalent bonds) Graphite structure: the carbon atoms are sp2 hybridized. They are connected by and bonds to form a giant network: the electrons are able to delocalize over the entire sheet, since sp2 hybridization is trigonal planar, graphite forms flat sheets of carbon rings. They are held together by dispersion forces from the electrons. It is soft because the sheets can slide past each other.