(2) Examine the models of the lattice of ZnS (zinc bende) and Fe metal on display. a) Write the type of unit cell for ZnS: ( S is black and Zn is light colored) b) What is the packing of the S atom in the ZnS? (See MicMurry \& Fay, P. 374, Table 10.10) c) What is the coordination number (CN) of Zn : d) How many Zn atoms are there in a unit cell of ZnS ? e) There is another form of ZnS called "wurtzite". How is it different from zinc blende? Zn blende: Wurtzite: a) Write the type of unit cell for Fe: b) What is the CN for each Fe atom? 3) Examine the models of the covalent network solids, diamond, graphite and ice on display. The white straws represent London dispersion forces in the graphite model and hydrogen bonding in ice. a) What is the hybridization of the C atoms in diamond and graphite? Diamond: Graphite