An element has a body centered cubic structure with a unit cell edge length of 400 pm. Atomic mass of an element is `24 gmol^(-1)` What is the density of the element? `(N_A = 6 times 10^23 mol^-1)`

Options

A. `2 . 50 g cm^(-3)`
B. `1.80 g cm^(-3)`
C. `3 . 60 g cm ^(-3)`
D. `1.25 g cm^(-3)`

Answer

D

Explanation

Given, edge length (a) = 400 pm
` 400 xx 10^(-10)`
M(atomic mass) `= 24 g mol^(-1)`
`N_(A) = 6 xx 10^(23) mol^(-1)`
`:. ` Density (d) ` = (Z xx M)/(a^(3) xx N_(A))`
`d = (2 xx 24)/((400 xx 10^(-10))^(3) xx 6 xx 10^(23))`
`d = 1.25 g cm^(-3)`