Gold has a close packed structure which can be reviewed as sphere occupying 0.74 of the total volume. If the density of gold is 19.3 g/cc. Calculate the apparent radius of a gold atom in the solid(Au = 197 amu)/

Gold has a close packed structure which can be reviewed as sphere occu

1.	Gold has a close packed structure which can be reviewed as sphere occupying 0.74 of the total volume. If the density of gold is 19.3 g/cc. Calculate the apparent radius of a gold atom in the solid(Au = 197 amu)/
Answer» SOLUTION :As the packing fraction is 0.74 , packing can be hcp or FCC. KNOWING that gold has fcc lattice, Z = 4 p = ` ( Z xx M)/ (a^(3) xx N_(0))therefore19.3 = ( 4 xx 197)/ (a^(3)xx 6.023 xx 10^(23))ora= 4.07 xx 10^(-8) ` CM For fcc, ` r = a / (2sqrt2)= ( 4.07 xx 10^(-8))/ (2xx 1.414)= 1.439 xx 10^(-8) ` cm