Looking at Figure 12.27 identify the coordination numbers
of the Cu, Y, and Ba atoms.


Verified Solution

Key Concepts
Coordination Number
Crystal Lattice Structure
Ionic and Metallic Bonding
Wide band-gap semiconductors have a band gap between 2 and 7 electron volts (eV), where 1 eV = 96.485 kJ/mol. The wide band-gap semiconductor GaN, used to construct the laser in Blu-ray DVD players, has a band gap of 3.44 eV. The material in the laser, GaxIn1-xN, has some indium substituted for gallium. (b) If the light from the device is blue, does partial substitution of indium for gallium increase or decrease the band gap of GaxIn1-xN compared to GaN?
The YBa2Cu3O7 superconductor can be synthesized by the solgel method from a stoichiometric mixture of metal ethoxides followed by heating in oxygen. How many grams of Y(OCH2CH3)3 and how many grams of Ba(OCH2CH3)2 are required to react with 75.4 g of Cu(OCH2CH3)2 and an excess of water? Assuming a 100% yield, how many grams of YBa2Cu3O7 are obtained?