An element (atomic mass = 100 `//` mol) having bcc structure has unit cell edge 400 pm. The density of the element is `:`

Options

A. `10.376g cm^(-3)`
B. `5.1888 g cm^(-3)`
C. `7.289 g cm^(-3)`
D. `2.144 g cm^(-3)`

Answer

B

Explanation

Density , `d = ( Z xx M)/( a^(3) xx N_(A))`
Z = 2 ( bcc), M 100 g `mol^(-1)`
a = `400 xx 10^(-10) cm = 4 xx 10^(-8) cm`,
`N_(A) = 6.02 xx 10^(23)`
`:. d = ( 2 xx 100)/( ( 4 xx 10^(-8))^(3) xx ( 6.02 xx 10^(23)))`
`= 5.19 g cm^(-3)`