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

Options

A. `454kg//m^(3)`
B. `804kg//m^(3)`
C. `852kg//m^(3)`
D. `910kg//m^(3)`

Answer

D

Explanation

For bcc, `d=(sqrt(3))/(2)a`
or `a=(2d)/(sqrt(3))=(2xx4.52)/(1.732)`
`=5.219` Å
=522 pm
`rho=(ZxxM)/(a^(3)xxN_(0))`
`=(2xx39)/((5.22)^(3)xx(6.02xx10^(23))xx10^(-3))`
`=910kgm^(-3)`