Lithium has a bcc structure. Its density is 530 kgm^(-3)and its atomic mass is6. 94 g mol^(-1) . Calculate the edge length of the unit cell of calculate the edge length of the unit cell of lithium metal(N_(A) = 6.02 xx 10^(23) mol^(-1))

Lithium has a bcc structure. Its density is 530 kgm^(-3)and its atomic

1.	Lithium has a bcc structure. Its density is 530 kgm^(-3)and its atomic mass is6. 94 g mol^(-1) . Calculate the edge length of the unit cell of calculate the edge length of the unit cell of lithium metal(N_(A) = 6.02 xx 10^(23) mol^(-1))
Answer» 527 pm 264 pm 154 pm 352 pm Solution :When a is in pm and other quantities oin CGS units, we have ` p = ( Z XX M)/( a^(3) xx N_(0)xx 10^(-30))g//cm^(3)` for bcc,Z =2 ,M = 6.94 ` g " mol"^(-1)` ` p = 530 kg m^(-3) = ( 530 xx 1000)/( 1xx (100)^(3) cm^(3)) = 0.53 " gcm"^(-3)` `a^(3) = ( 2 xx 6.94)/( 0.53 xx6.02 xx 10^(23) xx 10^(-30))` ` = 4.35xx 10^(7) =43.5 xx 10^(6)` `a= ( 43.5)^(1//3) xx 10^(2)= 3.52 xx 10^(2) "pm" = 352 "pm" `