Lithium has a bcc structure . Its density is 530 kg m^(-3) and the its atomic mass is 6.94 g mol^(-1) . Calculate the edge length of the unit cell of lithium metal (N_A=6.02xx10^23 mol^(-1))

Lithium has a bcc structure . Its density is 530 kg m^(-3) and the its

1.	Lithium has a bcc structure . Its density is 530 kg m^(-3) and the its atomic mass is 6.94 g mol^(-1) . Calculate the edge length of the unit cell of lithium metal (N_A=6.02xx10^23 mol^(-1))
Answer» 527 pm 264 pm 154 pm 352 pm Solution :When a is in pm and other quantities in CGS units, we have `RHO=(ZxxM)/(a^3xxN_0xx10^(-30))G//cm^3` For bcc, Z=2 , M=`6.94 "g mol"^(-1)` , `rho=530 KG m^(-3)=(530xx1000)/(1xx(100)^3cm^3)=0.53 g cm^(-3)` `therefore a^3=(2xx6.94)/(0.53xx6.02xx10^23xx10^(-30))` `=4.35xx10^7=43.5xx10^6` `therefore a=(43.5)^(1//3)xx10^2 =3.52xx10^2` pm =352 pm