Question

.4 Draw the bcc unit cell of tungsten metal and add a second neighboring unit cell. What is the coordination number of a site in the face of the original unit cell? What would be the stoichiometry of a compound in which all these sites were filled with carbon? 3.5 Metallic sodium adopts a bce structure with density of 970 kg/m'. What is the length of the edge of the unit cell? 3.6 An alloy of copper and gold has the fcc structure in which Au at the corner and Cu in the face. Calculate the composition of the unit cell. Given that 24-carat gold is pure gold, what carat gold does this alloy represent? 3.7 Depending on temperature, RbCI can exist in either the rock salt or CsCI structure. (a) What is the coordination number of the cation and anion in each of these structures? (b) In which of these structures will Rb have the larger apparent radius?

Answer 1

Solc han BCC unit cell of tunasten metal atem ad he cendre cirit cell

mフ Cl 24 A 28 CYm nNen Cornen osition uint cel CF) hee ane 8 Acl- adom en the Comensecch adtoms conibuta/8 Total ne Auu-a-lom pea umt cell u-C aCe unit cel

DATE Composihm Cu: Au 3:1 A+ high bCl adop+ Cs C Crd he ame Co-oxcinaim A osoen elae 1 lin-Rock-d alt-saoudoe, the Cene atac aLo Co-on clonato numben ocs -Sat stro Ceti on Savi on cui.