Question

Potassium has a bcc structure with nearest neighour distance `4.52 Å`its atomic weight is `39` its density (in kg `m^(-3)`) will be
A. 454
B. 804
C. 852
D. 908

Answer 1

Correct Answer - D
For bcc, d`=sqrt(3)/(2)` a or `a=(2d)/sqrt(3)=(2xx4.52)/(1.732)=5.219overset(@)A`=522pm
`rho=(ZxxM)/(a^(3)xxN_(0)xx10^(-30))=(2xx39)/((522)^(3)xx(56.023xx10^(23))xx10^(-30))`
`=0.91g//cm^(3)=910kgm^(-3)`